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Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_14 | Pages 11 - 11
23 Jul 2024
Sarhan M Moreau J Francis S Page P
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Hip fractures frequently occur in elderly patients with osteoporosis and are rapidly increasing in prevalence owing to an increase in the elderly population and social activities. We experienced several recent presentations of TFNA nails failed through proximal locking aperture which requires significant revision surgery in often highly co-morbid patient population.

The study was done by retrospective data collection from 2013 to 2023 of all the hip fractures which had been fixed with Cephalomedullary nails to review and compare Gamma (2013–2017) and TFNA (2017–2023) failure rates and the timing of the failures. Infected and Elective revision to Arthroplasty cases were excluded.

The results are 1034 cases had been included, 784 fixed with TFNA and 250 cases fixed Gamma nails. Out of the 784 patients fixed with TFNA, 19 fixation failed (2.45%). Out of the 250 cases fixed with Gamma nails, 15 fixation failed (6%). Mean days for fixation failure were 323 and 244 days in TFNA and Gamma nails respectively.

We conclude that TFNA showed remarkable less failure rates if compared to Gamma nails. At point of launch, testing was limited and no proof of superiority of TFNA over Gamma nail. Several failures identified with proximal locking aperture in TFNA which can be related to the new design which had Substantial reduction in lateral thickness at compression screw aperture.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_21 | Pages 90 - 90
1 Dec 2016
Schemitsch E Walmsley D McKee M Nauth A Waddell J
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Proximal femur fractures are increasing in prevalence, with femoral neck (FN) and intertrochanteric (IT) fractures representing the majority of these injuries. The salvage procedure for failed open reduction internal fixation (ORIF) is often a conversion to total hip arthroplasty (THA). The use of THA for failed ORIF improves pain and function, however the procedure is more challenging. The aim of this study was to investigate the clinical and radiographic outcomes in patients who have undergone THA after ORIF. This retrospective case-control study compared patients who underwent THA after failed ORIF to a matched cohort undergoing primary THA for non-traumatic osteoarthritis. From 2004 to 2014, 40 patients were identified. The matched cohort was matched for date of operation, age, gender, and type of implant. Preoperative, intraoperative, and postoperative data were collected and statistical analysis was performed. The cohort of patients with a salvage THA included 18 male and 22 female patients with a mean age of 73 years and mean follow up of 3.1 years. Those with failed fixation included 12 IT fractures and 28 FN fractures. The mean time between ORIF and THA was 2.1 years for IT fractures and 8.5 years for FN fractures (p=0.03). The failed fixation group had longer procedures, greater drop in hemoglobin, and greater blood transfusion rate (p<0.05). There was one revision and one dislocation in the failed fixation group with no revisions or dislocations in the primary THA group. Length of admission, medical complications, and functional outcome as assessed with a standardised hip score and were found not to be statistically different between the groups. Salvage THA for failed initial fixation of proximal femur fractures yields comparable clinical results to primary THA with an increased operative time, blood loss, and blood transfusion rate


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_8 | Pages 54 - 54
1 May 2014
Cameron H
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The S-ROM stem is distally circular canal filling with thin sharp flutes which engage the endosteal cortex. The rotational stability produced by this is 37 Nm, which exceeds the service loads on the hip of 22 Nm. The distal canal fill prevents varus and valgus displacement. The porous-coated proximal sleeve provides resistance to vertical sink and also excludes the distal stem from the effective joint space.

The primary stem is straight and the long stem is bowed with a 15 degrees anteversion twist proximally. The neck comes in lengths from 30 to 46mm with varying offset. The sleeves come in variable size and geometry.

The stem choice in revision surgery is based on the Scoot Diamond Classification. Type 1 (this is going to be easy) is a primary stem. Type 2 (this is going to be difficult) implies diaphyseal bone loss and will require a long stem. Type 3 (Oh My God), implies more than 70mm of completely missing proximal femur and will require a structural allograft cemented to the sleeve.

Results

The follow-up is from 2 to 22 years. There were 119 primary stems. Revisions for aseptic loosening were zero. One stem was removed for late sepsis at nine years.

There were 262 long stem cases. Stem revision for aseptic loosening occurred in nine cases (3.7%). Four became loose because of inappropriate and obsolete techniques of allografting, one for non-union of a subtrochanteric osteotomy and four for failure of ingrowth into the sleeve. Four were revised for late sepsis. Structural allografts comprised seven cases. Three were revised at years 7, 11 and 16.

Conclusion

The revision rate for aseptic loosening in hip revision cases is acceptably low.

Other issues such as late polyethylene wear and dislocation continue to decrease.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_2 | Pages 69 - 69
10 Feb 2023
Tong Y Holmes S Sefton1 A
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There is conjecture on the optimal timing to administer bisphosphonate therapy following operative fixation of low- trauma hip fractures. Factors include recommendations for early opportunistic commencement of osteoporosis treatment, and clinician concern regarding the effect of bisphosphonates on fracture healing. We performed a systematic review and meta-analysis to determine if early administration of bisphosphonate therapy within the first month post-operatively following proximal femur fracture fixation is associated with delay in fracture healing or rates of delayed or non-union. We included randomised controlled trials examining fracture healing and union rates in adults with proximal femoral fractures undergoing osteosynthesis fixation methods and administered bisphosphonates within one month of operation with a control group. Data was pooled in meta-analyses where possible. The Cochrane Risk of Bias Tool and the GRADE approach were used to assess validity. For the outcome of time to fracture union, meta-analysis of three studies (n= 233) found evidence for earlier average time to union for patients receiving early bisphosphonate intervention (MD = −1.06 weeks, 95% CI −2.01 – −0.12, I. 2. = 8%). There was no evidence from two included studies comprising 718 patients of any difference in rates of delayed union (RR 0.61, 95% CI 0.25–1.46). Meta-analyses did not demonstrate a difference in outcomes of mortality, function, or pain. We provide low-level evidence that there is no reduction in time to healing or delay in bony union for patients receiving bisphosphonates within one month of proximal femur fixation


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_7 | Pages 16 - 16
1 Apr 2017
Hozack W
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Despite the best of technique, when faced with a sub-capital or per-trochanteric fracture, inevitably there are failures of proximal fixation. These situations provide unique challenges for the reconstructive surgeon. While there are specific issues related to either sub-capital or per-trochanteric fractures, there also are many commonalities. The causes of failure are nonunion, malunion, failure of fixation or avascular necrosis. In all cases, it is imperative to rule out infection. Since the surgery is now elective, the patient's medical status must be optimised prior to the intervention. Basic surgical principles apply to both fracture types. Use the old incision (if possible) and choose an approach that can be extensile. Of course, the old hardware needs to be removed – this task can be quite frustrating, so good preparation and patience is imperative. Retrieve old operative notes to identify the type of hardware so that any special tools needed are available. Hardware can be intra-osseous in location and excavation of the hardware may require bone osteotomy. These patients are at higher risk of post-operative dislocation, so absolute hip stability must be achieved and confirmed in the OR. Bigger heads and dual mobility options improve stability provided that the components are properly positioned and offset and leg length are restored. Subcapital fractures provide certain specific issues related to stem choice. While, my bias is towards THA because of better chance of complete pain relief, especially in community ambulators, certainly bipolar arthroplasties can be a satisfactory solution. Stem fixation can be either cemented or cementless. For per-trochanteric fractures in younger patients, repeat osteosynthesis should be considered if the femoral head is viable. Bone deformity – trochanteric overhang, shaft offset – may necessitate an osteotomy as part of the reconstruction. While proximal fixation primary type stems are often possible, distal fixation revision stems may be required. Any bone defects related to screw holes should be bypassed by the femoral component


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_22 | Pages 16 - 16
1 Dec 2016
Hozack W
Full Access

Despite the best of technique when faced with a sub-capital or per-trochanteric fracture, inevitably there are failures of proximal fixation. These situations provide unique challenges for the reconstructive surgeon. While there are specific issues related to either sub-capital or per-trochanteric fractures, there also are many commonalities. The causes of failure are nonunion, malunion, failure of fixation or avascular necrosis. In all cases, it is imperative to rule out infection. Since the surgery is now elective, the patient's medical status must be optimised prior to the intervention. Basic surgical principles apply to both fracture types. Use the old incision (if possible) and choose an approach that can be extensile. Of course, the old hardware needs to be removed – this task can be quite frustrating, so good preparation and patience is imperative. Retrieve old OP notes to identify the type of hardware so that any special tools needed are available. Hardware can be intra-osseous in location and excavation of the hardware may require bone osteotomy. These patients are at higher risk of postoperative dislocation, so absolute hip stability must be achieved and confirmed in the OR. Bigger heads and dual mobility options improve stability provided that the components are properly positioned and offset and leg length are restored. Subcapital fractures provide certain specific issues related to stem choice. While, my bias is towards total hip arthroplasty because of better chance of complete pain relief, especially in community ambulators, certainly bipolar arthroplasties can be a satisfactory solution. Stem fixation can be either cemented or cementless. For per-trochanteric fractures in younger patients, repeat osteosynthesis should be considered if the femoral head is viable. Bone deformity – trochanteric overhang, shaft offset – may necessitate an osteotomy as part of the reconstruction. While proximal fixation primary type stems are often possible, distal fixation revision stems may be required. Any bone defects related to screw holes should be bypassed by the femoral component


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_9 | Pages 72 - 72
1 May 2016
Nadorf J Kinkel S Kretzer J
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INTRODUCTION. Modular knee implants are used to manage large bone defects in revision total knee arthroplasty. These implants are confronted with varying fixation characteristics, changes in load transfer or stiffen the bone. In spite of their current clinical use, the influence of modularity on the biomechanical implant-bone behavior (e.g. implant fixation, flexibility, etc.) still is inadequately investigated. Aim of this study is to analyze, if the modularity of a tibial implant could change the biomechanical implant fixation behavior and the implant-bone flexibility. MATERIAL & METHODS. Nine different stem and sleeve combinations of the clinically used tibial revision system Sigma TC3 (DePuy) were compared, each implanted standardized with n=4 in a total of 36 synthetic tibial bones. Four additional un-implanted bones served as reference. Two different cyclic load situations were applied on the implant: 1. Axial torque of ±7Nm around the longitudinal stem axis to determine the rotational implant stability. 2. Varus-valgus-torque of ±3,5Nm to determine the bending behavior of the stem. A high precision optical 3D measurement system allowed simultaneous measuring of spatial micromotions of implant and bone. Based on these micromotions, relative motions at the implant-bone-interface and implant flexibility could be calculated. RESULTS. Lowest relative micromotions were measured along the tibial base component and the sleeve; however, these motions varied depending on the implant construct used. Maximum relative micromotions were detected at the distal end of the implant for all groups, indicating a more proximal fixation of all modular combinations. Regarding varus-valgus-torque measurement, all groups showed a deviant flexibility behavior compared to the reference group. When referred to the un-implanted bone, implants without stems revealed the highest flexibility, whereas implants with shorter stems had lowest flexibility. DISCUSSION & CONCLUSION. All groups showed a more proximal fixation behavior; moreover, both extent and location of fixation could be influenced by varying the modular combination. Larger stems seemed to support a more distal fixation behavior, whereas the implant fixation moved proximal while extending the sleeve. Here the influence of the sleeve on fixation behavior seemed to be dominant compared to the influence of the stem. Concerning varus-valgus-torque, a strong connection between the used stem and implant-bone flexibility seemed to exist. In addition, the influence of the sleeve on flexibility seemed to be rather low. This study showed, that modularity can influence the biomechanical behavior of tibial implants. If these results can be transferred to other tibial implants still remains to be seen


The Bone & Joint Journal
Vol. 106-B, Issue 3 | Pages 293 - 302
1 Mar 2024
Vogt B Lueckingsmeier M Gosheger G Laufer A Toporowski G Antfang C Roedl R Frommer A

Aims

As an alternative to external fixators, intramedullary lengthening nails (ILNs) can be employed for distraction osteogenesis. While previous studies have demonstrated that typical complications of external devices, such as soft-tissue tethering, and pin site infection can be avoided with ILNs, there is a lack of studies that exclusively investigated tibial distraction osteogenesis with motorized ILNs inserted via an antegrade approach.

Methods

A total of 58 patients (median age 17 years (interquartile range (IQR) 15 to 21)) treated by unilateral tibial distraction osteogenesis for a median leg length discrepancy of 41 mm (IQR 34 to 53), and nine patients with disproportionate short stature treated by bilateral simultaneous tibial distraction osteogenesis, with magnetically controlled motorized ILNs inserted via an antegrade approach, were retrospectively analyzed. The median follow-up was 37 months (IQR 30 to 51). Outcome measurements were accuracy, precision, reliability, bone healing, complications, and patient-reported outcome assessed by the Limb Deformity-Scoliosis Research Society Score (LD-SRS-30).


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_22 | Pages 54 - 54
1 May 2013
Cameron H
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Femoral components in total hip replacements fail in well-known ways. There is vertical sink, posterior rotation and pivot, either distal or mid-stem. In order to sink, the stem moves into valgus and then slides down the inside of the calcar. It does not cut through the calcar. To prevent sink and pivot, a canal filling stem is required. Canal fill prevents the stem from moving into valgus and, therefore, it will not sink. Two centimeters with complete canal fill is adequate in a primary stem. A long stem will give longer canal fill in a revision. Sharp distal flutes will prevent rotation. The distal end of the stem should be polished. One is looking for a distal stability, not distal fixation. If the isthmus is intact, a primary stem can be used. If the isthmus is damaged, a long stem is necessary. If the calcar is intact, a primary neck is adequate. If the calcar is missing down to the level of the lesser trochanter, a calcar replacement neck is required. If there is more than 70 millimeters of completely missing proximal femur, a structural allograft is required. If the proximal femur is damaged, the ability to place a sleeve or collar to seek the best bone available independently of the stem version is very helpful. No matter how poor the proximal bone quality is, it can be supplemented by cerclage wires. The implant will sink only if the cerclage wires break. The advantage of proximal fixation is that loading the proximal femur speeds recovery. The huge disadvantage of distal fixation is removal of the implant should it become necessary. My long term results for the S-ROM stem used in revision are now out over 20 years. There were 119 primary stems with a minimum follow up of 5 years with no revisions for aseptic loosening. There were 262 long stems used. Nine (3.7%) underwent aseptic loosening. Most of these were due to technical errors due to my inexperience in the learning process of revision surgery. Four were dependent on strut-grafts and should have been treated with structural allografts. There were seven cases with structural allografts. Three were revised. Again, these were largely from problems arising from inexperience. I believe proximal modularity with distal stability allows the vast majority of revision cases to be treated with proximal fixation


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_10 | Pages 19 - 19
1 Jun 2018
Garbuz D
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Intra-operative fractures of the femur are on the rise mainly due to the increased use of cementless implants and the desire to get a tight press fit. The prevalence has been reported to be between 1–5% in cementless THAs. The key to preventing these fractures is to identify patients at high risk and careful surgical technique. Surgical risk factors include the use of cementless devices, revision hip surgery, the use of flat tapered wedges and MIS surgery. Patient factors that increased risk include increasing age, female gender, osteopenia and rheumatoid arthritis. These risk factors tend to be additive and certainly when more than one is present extra caution needs to be taken. Surgical technique is critical to avoid these intra-operative fractures. Fractures can occur during exposure and dislocation, during implant removal (in revision THA), during canal preparation and most commonly during stem insertion. In both primary, and especially in revision, THA be wary of the stiff hip in association with osteopenia or osteolysis. These patients require a very gentle dislocation. If this cannot be achieved, then alteration of the standard approach and dislocation may be needed. Examples of these include protrusion with an osteopenic femur and revision THA with a very stiff hip with lysis in the femur. Lastly, in cases with retained hardware, dislocate prior to removing plates and screws. After dislocation, the next challenge is gentle preparation of the femoral canal. A reasonable exposure is required to access the femoral canal safely. MIS procedures do not offer good access to femoral canal and this probably results in increased risk of fracture during broaching or implant insertion. When broaching, stop when broach will not advance further. When inserting a tapered wedge stem, be worried if stem goes further in than broach. In revision surgery, when taking the stem out from above, make sure the area of the greater trochanter does not overhang the canal. A high speed burr can clear the shoulder for easier access for removal. In revision THA with an ETO, place a cerclage wire prior to reaming and retighten prior to stem insertion. Even with careful surgical technique intra-operative femoral fractures will still occur. When inserting the stem, a sudden change in resistance is highly suggestive of fracture. Wide exposure of the entire proximal femur is necessary to confirm the diagnosis. The distal extent of the fracture must be seen. Only on occasion is an intra-operative radiograph needed. Management is directed to ensuring component stability and good fracture fixation. In primary total hip arthroplasty, calcar fractures are by far the most common. If using proximal fixation and you are certain the stem is stable, then all that is needed is cerclage wiring. As already mentioned, you must follow the fracture line distally so you are aware of how far down it goes. Often what appears to be a calcar split actually propagates distal to the lesser trochanter. In these cases, one would probably go for distal fixation plus wiring. In conclusion, intra-operative femoral fractures are on the rise. Prevention is the key


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_7 | Pages 10 - 10
1 Apr 2017
Su E
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In recent years, cementless stems have dominated the North American market. There are several categories of cementless stems, but in the past 20 years, the two most popular designs in the United States have been the extensively coated cylindrical cobalt-chrome (CoCr) stem and the proximally coated tapered titanium stem, which in recent years has become the most common. The 10-year survival for both stem types has been over 95% with a distinction made on factors other than stem survival, including thigh pain, stress shielding, complications of insertion, and ease of revision. Conventional wisdom holds that proximally coated titanium stems have less stress shielding, less thigh pain, and a higher quality clinical result. Recent studies, however, including randomised clinical trials have found that the incidence of thigh pain and clinical result is essentially equivalent between the stem types, however, there is a modest advantage in terms of stress shielding for a tapered titanium stem over an extensively coated CoCr stem. One study utilizing pain drawings did establish that if a CoCr cylindrical stem was utilised, superior clinical results in terms of pain score and pain drawings were obtained with a fully coated versus a proximally coated stem. In spite of the lack of a clinically proven advantage in randomised trials, tapered titanium stems have been favored because of the occasional occurrence of substantial stress shielding, the increased clinical observation of thigh pain severe enough to warrant surgical intervention, ease of use of shorter tapered stems that involve removal of less trochanteric bone and less risk of fracture both at the trochanter and the diaphysis due to the shorter, and greater ease of insertion through more limited approaches, especially anterior approaches. When tapered stems are utilised, there may be an advantage to a more rectangular stem cross-section in patients with type C bone. In spite of the numerous clinical advantages of tapered titanium stems, there still remains a role for more extensively coated cylindrical stems in patients that have had prior surgery of the proximal femur, particularly for a hip fracture, which makes proximal fixation, ingrowth, and immediate mechanical stability difficult to assure consistently. Cement fixation should also be considered in these cases. While the marketplace and the clinical evidence strongly support routine use of tapered titanium proximally coated relatively short stems with angled rather than straight proximal lateral geometry in the vast majority of cases, there still remains a role for more extensively coated cylindrical and for specific indications


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_7 | Pages 19 - 19
1 Apr 2017
Garbuz D
Full Access

Intra-operative fractures of the femur are on the rise mainly due to the increased use of cementless implants and the desire to get a tight pressfit. The prevalence has been reported to be between 1–5% in cementless total hip arthroplasties (THAs). The key to preventing these fractures is to identify patients at high risk and careful surgical technique. Surgical risk factors include the use of cementless devices, revision hip surgery, the use of flat tapered wedges and MIS surgery. Patient factors that increased risk include increasing age, female gender, osteopenia and rheumatoid arthritis. These risk factors tend to be additive and certainly when more than one is present extra caution needs to be taken. Surgical technique is critical to avoid these intra-operative fractures. Fractures can occur during exposure and dislocation, during implant removal (in revision THA), during canal preparation and most commonly during stem insertion. In both primary and especially in revision THA, be wary of the stiff hip in association with osteopenia or osteolysis. These patients require a very gentle dislocation. If this cannot be achieved, then alteration of the standard approach and dislocation may be needed. Examples of these include protrusion with an osteopenic femur and revision THA with a very stiff hip with lysis in the femur. Lastly, in cases with retained hardware, dislocate prior to removing plates and screws. After dislocation, the next challenge is gentle preparation of the femoral canal. A reasonable exposure is required to access the femoral canal safely. MIS procedures do not offer as good access to femoral canal and this probably results in increased risk of fracture during broaching or implant insertion. When broaching, stop when broach will not advance further. When inserting a tapered wedge stem, be worried if stem goes further in than broach. In revision surgery when taking the stem out from above, make sure the greater trochanter does not overhang the canal. A high speed burr can clear the shoulder for easier access for removal. In revision THA with an ETO place a cerclage wire prior to reaming and retighten prior to stem insertion. Even with careful surgical technique intra-operative femoral fractures will still occur. When inserting the stem a sudden change in resistance is highly suggestive of fracture. Wide exposure of the entire proximal femur is necessary to confirm the diagnosis. The distal extent of the fracture must be seen. Only on occasion is an intra-operative radiograph needed. Management is directed to ensuring component stability and good fracture fixation. In primary total hip arthroplasty calcar fractures are by far the most common. If using proximal fixation and you are certain the stem is stable, then all that is needed is cerclage wiring. As already mentioned, you must follow the fracture line distally so you are aware of how far down it goes. Often what appears to be a calcar split actually propagates distal to the lesser trochanter. In these cases, one would probably go for distal fixation plus wiring. In conclusion intra-operative femoral fractures are on the rise. Prevention is the key. If a fracture, exposure is the key to deciding on a treatment plan


Orthopaedic Proceedings
Vol. 97-B, Issue SUPP_1 | Pages 104 - 104
1 Feb 2015
Haidukewych G
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Periprosthetic fractures around a TKA typically involve the distal femur above a well-fixed femoral component. ORIF is typically indicated, using a retrograde nail or some form of locked plating. Tibial fractures after TKA are quite rare. In distinction to femoral fractures, fractures around a tibial component are typically associated with a loose prosthesis. Revision is indicated in this situation. Dealing with bone loss with augments, sleeves, cones, or allograft as well as stem bypass is typically necessary. Varus malalignment is often noted in these situations and should be corrected. More distal fractures can be managed with closed treatment if displacement and angulation is acceptable. A period of time in a long leg cast followed by conversion to a short leg or so-called PTB cast can be effective. More unstable fractures can be managed with plating techniques. Percutaneous so called MIPPO techniques can be particularly useful. Modern locking plates allow polyaxial proximal fixation that can be effective around the keels of tibial components. Malalignments are common so careful fluoroscopic scrutiny is necessary when using percutaneous techniques


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_22 | Pages 66 - 66
1 Dec 2016
Gehrke T
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Periprosthetic fractures involving the femoral meta/diaphysis can be treated in various fashions. The overall incidence of those fractures after primary total knee arthroplasties (TKA) ranges from 0.3 to 2.5%, however, can increase above 30% in revision TKA, especially in older patients with poorer bone quality. Various classifications suggest treatment algorithms. However, they are not followed consequently. Revision arthroplasty becomes always necessary if the implant becomes loose. Next, it should be considered in case of an unhappy TKA prior to the fracture rather than going for an osteosynthesis. Coverage of the associated segmental bone loss in combination with proximal fixation, can be achieved in either cemented or non-cemented techniques, with or without the combination of osteosynthetic fracture stabilization. Severe destruction of the metaphyseal bone, often does not allow adequate implant fixation for the revision implant and often does not allow proper anatomic alignment. In addition the destruction might include loss of integrity of the collaterals. Consequently standard or even revision implants might not be appropriate. Although first reports about partial distal femoral replacement are available since the 1960´s, larger case series or technical reports are rare within the literature and limited to some specialised centers. Most series are reported by oncologic centers, with necessary larger osseous resections of the distal femur. The implantation of any mega prosthesis system requires meticulous planning, especially to calculate the appropriate leg length of the implant and resulting leg length. After implant and maybe cement removal, non-structural bone might be resected. Trial insertion is important due to the variation of overall muscle tension and recreation of the former joint line. So far very few companies offer yet such a complete, modular system which might also be expanded to a total femur solution. Furthermore it should allow the implantation of either a cemented or uncemented diaphyseal fixation. In general, the fracture should be well bridged with a longer stem in place. At least 3 cm to 5 cm of intact diaphysis away to the fracture site is required for stable fixation for both cemented and cementless stems. Application of allograft struts and cables maximises the biomechanical integrity of the fracture zone to promote fracture repair and implant fixation. Modular bridging systems do allow centimeter wise adaption distally, to the knee joint. Consequently in modern systems fully hinged or rotational hinge knee systems can be coupled, and adjusted accordingly to the patellar tracking and joint line. Fixation of the tibial component can be achieved in uncemented and cemented techniques. We still prefer the latter. Although a reliable and relatively quick technique, frequent complications for all mega systems have been described. These usually include infections, rotational alignment and loosening of the femoral fixation or subsequent proximal femoral fractures. Infections usually can be related to large soft tissue compromise or extensive exposure or longer procedure times. Thus implantation of such reconstruction systems should be reserved to specialised centers, with adequate facilities experience, in order to minimise complications rates and optimise patients function postoperative


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_6 | Pages 45 - 45
1 Mar 2017
Tarallo L Mugnai R Catani F
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Background. Currently, stailess steel, titanium and carbon-fiber reinforced polyetheretherketone (CF-PEEK) plates are available for the treatment of distal radius fractures. Since the possibility to create a less rigid fixation may represent an advantage in case of ostheoporotic or poor quality bone, the aim of this study is to compare the biomechanical properties of these three materials in terms of bending stiffness with a single static load and after cyclical loading, simulating physiologic wrist motion. Materials and Methods. Three volar plating systems with fixed angle were tested: Zimmer stainless steel volar lateral column (Warsaw, IN); Hand Innovations titanium DVR (Miami, FL); Lima Corporate CF-PEEK DiPHOS-RM (San Daniele Del Friuli, Udine, Italy). For each type of plate tested four right synthetic composite bone radii were used. An unstable, extraarticular fracture was simulated by making an 8 mm gap with a saw starting 12 mm proximal to the articular surface of the radius on the distal radio-ulnar joint side. The osteotomies were made perpendicular to the long axis of the bone to allow for a consistent fracture gap on the dorsal and volar sides of the radius. Plates were implanted using all the distal and proximal fixation holes [Fig. 1]. Each synthetic radius model was potted in methylmethacrylate and tested in a bi-axial servo-hydraulic test frame (MTS Minibionix 858, universal testing machine) for load to failure by advancing a cobalt chrome sphere centered over the articular surface at a constant rate of displacement of 5 mm/min. The sphere was advanced until the construct failed or the dorsal edges of the fracture met. The resultant force was defined as bending stiffness pre fatigue. Three constructs for each plate were then dynamically loaded for 6000 cycles of fatigue at a frequency of 10Hz, with a load value corresponding to the 50% of the previously calculated bending strength. Finally, the constructs were loaded to failure, measuring the bending stiffness post fatigue. Results. All fracture constructs survived all phases of the cyclic loading testing. The mean bending stiffness pre fatigue was higher for the Zimmer plate (155.23±1.91 N/mm), in comparison to Hand Innovations (138.67±4.72 N/mm), and DiPHOS-RM (124.75±3.60 N/mm) [Fig. 2]. After cyclic loading, stiffness increased significantly of a mean 24% for the Zimmer plate (190.42±4.33 N/mm); 33% for the Hand Innovations (186.57±1.71 N/mm); and 18% for the DiPHOS-RM (146.28±1.52 N/mm) [Fig. 2–3]. Conclusions. CF-PEEK plate is less stiff than stainless steel and titanium plates, with an elastic modulus more similar to bone as well as the ability to withstand prolonged fatigue strain. From these preliminary data it might be assumed that the CF-PEEK plates could provide a sufficiently stable osteosynthesis, flexible enough to unload the implant-bone interface, minimising peak stresses at the bone- implant interface, making them particularly suitable for fracture fixation in osteoporotic patients. A proper patient selection (avoiding incompliant or non collaborative) should be performed using CF-PEEK plates to avoid possible implant breakage consequent to a fall or a second trauma on the injuried wrist until the complete fracture healing. For any figures or tables, please contact authors directly (see Info & Metrics tab above).


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_22 | Pages 52 - 52
1 Dec 2016
Cameron H
Full Access

There is no mathematical relationship between the internal diameter of the femoral metaphysis and diaphysis. Unless an infinite number of monolithic stems are available with variable metaphyseal and diaphyseal diameters, which is not economically possible, even in virgin cases, the surgeon has to decide if the stem is going to fit in the metaphysis or the diaphysis. It is not possible to match both. In revision cases with a hollowed out metaphysis, the situation is much worse. As it is obviously easier to fit the diaphysis, this is what stems such as the AML and Wagner stem have done. They completely ignore the metaphysis and obtain fixation in the diaphysis. This is all well and good, but it means that the proximal femur is unloaded, like an astronaut in space. While, there will be some recovery due to removal of the toxins and local muscle pull, it will be incomplete. Furthermore, should sepsis occur, one is faced with the horror of removing a distally fixed implant. Clearly, if proximal fixation, i.e. above the level of lesser trochanter could reliably be achieved, this would be preferable in terms of proximal loading leading to bone recovery and ease of removal should it be required. The only way that proximal loading can be achieved is if the metaphyseal and diaphyseal parts of the component can be varied infinitely. This clearly can only be achieved by using a modular stem. The concern with modularity always has been fretting at the sleeve-stem locking mechanism with release of metal ions. The stem, which I have been using for the last 25 years, is the SROM stem. Fretting and ion release had never been an issue. As the components are made of a relatively soft titanium alloy, it is likely that the sleeve and the stem cold weld, thus, eliminating any movement and eliminating friction. I have a follow-up of roughly 120 revision cases with a minimum follow-up of 5 years and a maximum follow-up of 22 years. I have no loosening in easy revision cases where a primary stem was used. I have had some loosenings in extremely difficult revision situations where a long bowed stem was required, but even then, the loosening rate is less than 3%. I use this stem in primary situations, i.e. in about 80% of all the primaries I have done. This means I have done roughly 1500 cases or more. Other than some late infections, I have never, ever had any stem loosening in a simple case. Obviously, I have had loosenings in some cases, where we have been doing fancy shortening or de-rotation osteotomies, but none in simple primary cases. I would, therefore, suggest that the surgeon, if he wishes to use this stem, please try it out on some simple primary cases. The ability to vary distal and proximal internal diameters and proximal geometry makes for easy surgery. I have been using this stem for 25 years and continue to use it in all my primary noncemented cases. I believe in the adage of “train hard and fight easy.” I think that surgeons should not get themselves into a situation where they are forced in a difficult case to use something they have never seen before


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_12 | Pages 82 - 82
1 Jul 2014
Haidukewych G
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Peri-prosthetic fractures of the femur around a THA remain challenging injuries to treat. The Vancouver Classification helps to guide decision making, and is based on fracture location, implant fixation status, and remaining bone quality. It is critical to determine fixation status of the implant, even if surgical dislocation is necessary. Type A fractures involve the trochanters, and are usually due to osteolysis. Revision of the bearing surface and bone grafting of the lesions can be effective. Type B1 fractures occur around a well fixed stem, typically at the stem tip. Internal fixation with laterally based locked cable plates is effective. Optimising proximal fixation is important, typically with locked screws and cables. Allograft struts are probably unnecessary with modern angle stable plates. Type B2 and B3 fractures are treated with revision, either with a fully coated cylindrical or a modular fluted tapered titanium stem. Distal fixation should be optimised, while preserving vascularity to proximal bony fragments. The « internal scaffold » technique has been described with excellent results. Rarely, a proximal femoral replacement is necessary. Careful attention to detail and clear knowledge of stem fixation status is necessary for a good outcome


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_4 | Pages 79 - 79
1 Jan 2016
Tsujimoto T Hashimoto Y Ando W Koyama T Yamamoto K Ohzono K
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INTRODUCTION. The concept of anatomical stam is fit-and-fill in the proximity of the femur and to expect wall fixation, following to reduce thigh pain and stress shielding. Although the femoral medullary form and size are different in each races. CentPillar TMZF stem (stryker . ®. ) is anatomical stem designed based on computer-tomography of Japanese femurs. The purpose of this study was to evaluate clinical and radiographic outcomes of CentPillar TMZF stem at a mean of 3.6 years postoperatively. METHODS. We asseses the results of 98 primary total hip arthroplasty (THA) performed using a CentPillar TMZF stem in 91 Japanese patients (4 males, 94 females) undergoing surgery between August 2007 and June 2011, the mean age at the time of surgery was 62.0 (41–81) years old. The Diagnosis were osteoarthritis (OA) in 91 hips, rapidly destructive coxopathy (RDC) in 4 hips, rheumatoid arthritis (RA) in 3 hips. Clinical and radiographic assessments were performed for every patient for every follow up using Japan Orthopaedic Association (JOA) Score, thigh pain, revision surgery and complications. Radiographic assessments were including stem alignment on anteroposterior radiograph, stress shielding, bone remodeling, radiolucent line, osteolysis, loosening and subsidence. RESULTS. 50.7 points of the postoperative mean JOA score was significantly improved to 96.3 points postoperatively. No patients showed thigh pain. Intraoperative calcar fracture was occurred in 1 hip. In 97 hips of 98 hips (98%) stem was implanted in neutral position (within ±3 degrees). With regard to stress shielding, 69 hips (70%) had none or only 1. st. degree resorption; 29 hips (30%) had 2. nd. degree and no cases had 3. rd. and 4. th. degree. Spot welds were developed in 71 hips (71%; Gruen zone 2 and 6), and cortical hypertrophy were observed in 2 hips (2%; Gruen zone 3 and 5). No cases developed radiolucent line, osteolysis, loosening, and subsidence. No revision surgery were requied up to 5.8 years postoperatively. DISCUSSION AND CONCLUSION. CentPillar TMZF stem provided a stable fixation, with excellent short-term clinical and radiographic outcomes. The strong proximal fixation was predictably enabled, and there were few cases fixed distal portion of the femur. These finding suggested CentPillar TMZF stem fits Japanese medullary form and can expect the long-term survival


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_15 | Pages 354 - 354
1 Mar 2013
van der Rijt A Solaiman R van der Rijt R
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Conventional hip arthroplasty femoral stems bypass the femoral neck for fixation. The femoral neck and proximal femur has a complex anatomy and interosseous structure to facilitate transfer of mechanical load in axial, compression bending and torsion mechanisms. von Mises analysis suggests a short stem, fixed in the femoral neck would maintain proximal femoral biomechanics, achieve physiological load transfer to the femoral neck and preserve bone stock and function. The strong calcar bone provides excellent opportunities for implant fixation and load transfer. Method. The Muscle Sparing Arthroplasty (MSA™) is a short femoral stem designed to achieve implant fixation in the femoral neck. The specific design features including a trapezoidal cross section; proximal conical flare; porous coating and lateral T back enhance proximal fixation and compressive load transfer to the calcar and femoral neck. Results. We report 54 hip arthroplasties in 49 patients with an average follow up of 18 months. All hip arthroplasties showed evidence of new bone formation in the proximal femoral neck and calcar region. This consisted of new bone streaming from the original calcar bone, in a strut fashion up to the conical flare of the implant. In 18 patients additional new bone formation occurred proximal to the neck osteotomy. This pattern of bone formation is consistent with predictions. Conclusion. A short femoral stem, fixed in the femoral neck can maintain biomechanical function of the femoral neck and result in preservation of bone and new bone stock


Orthopaedic Proceedings
Vol. 97-B, Issue SUPP_1 | Pages 10 - 10
1 Feb 2015
Su E
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In recent years, cementless stems have dominated the North American market. There are several categories of cementless stems, but in the past 20 years, the two most popular designs in the United States have been the extensively coated cylindrical cobalt-chrome (Co-Cr) stem and the proximally coated tapered titanium stem, which in recent years has become the most common. The 10-year survival for both stem types has been over 95% with a distinction made on factors other than stem survival, including thigh pain, stress shielding, complications of insertion, and ease of revision. Conventional wisdom holds that proximally coated titanium stems have less stress shielding, less thigh pain, and a higher quality clinical result. Recent studies, however, including randomised clinical trials have found that the incidence of thigh pain and clinical result is essentially equivalent between the stem types, however, there is a modest advantage in terms of stress shielding for a tapered titanium stem over an extensively coated Co-Cr stem. One study utilising pain drawings did establish that if a Co-Cr cylindrical stem was utilised, superior clinical results in terms of pain score and pain drawings were obtained with a fully coated versus a proximally coated stem. In spite of the lack of a clinically proven advantage in randomised trials, tapered titanium stems have been favored because of the occasional occurrence of substantial stress shielding, the increased clinical observation of thigh pain severe enough to warrant surgical intervention, ease of use of shorter tapered stems that involve removal of less trochanteric bone and less risk of fracture both at the trochanter and the diaphysis due to the shorter, and greater ease of insertion through more limited approaches, especially anterior approaches. When tapered stems are utilised, there may be an advantage to a more rectangular stem-cross section in patients with type C bone. In spite of the numerous clinical advantages of tapered titanium stems, there still remains a role for more extensively coated cylindrical stems in patients that have had prior surgery of the proximal femur, particularly for a hip fracture, which makes proximal fixation, ingrowth, and immediate mechanical stability difficult to assure consistently. Cement fixation should also be considered in these cases. While the marketplace and the clinical evidence strongly support routine use of tapered titanium proximally coated relatively short stems with angled rather than straight proximal lateral geometry in the vast majority of cases, there still remains a role for more extensively coated cylindrical and for specific indications