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The Journal of Bone & Joint Surgery British Volume
Vol. 91-B, Issue 2 | Pages 180 - 184
1 Feb 2009
Lim HC Bae JH Hur CR Oh JK Han SH

We retrospectively evaluated eight patients who underwent arthrodesis of the knee using cannulated screws. There were six women and two men, with a mean age of 53 years. The indications for arthrodesis were failed total knee arthroplasty, septic arthritis, tuberculosis, and recurrent persistent infection. Solid union was achieved in all patients at a mean of 6.1 months. One patient required autogenous bone graft for delayed union. One suffered skin necrosis which was treated with skin grafting. The mean limb-length discrepancy was 3.1 cm. On a visual analogue scale, the mean pain score improved from 7.9 to 3.3. According to the Knee Injury and Osteoarthritis Outcome score quality of life items, the mean score improved from 38.3 pre-operatively to 76.6 at follow-up. Cannulated screws provide a high rate of union in arthrodesis of the knee with minimal complications, patient convenience, and a simple surgical technique


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_14 | Pages 45 - 45
1 Mar 2013
Seeger J Haas D Jäger S Clarius M
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Introduction. Periprosthetic medial tibial plateau fractures (TPF) are rare but represent a serious complication in unicompartmental knee arthroplasty (UKA). Most common treatment of these fractures is osteosynthesis with canulated screws or plates. Aim. The aim of this study was to evaluate these two different treatment options of periprosthetic fractures. The hypothesis was that osteosynthetic treatment with plates show significantly higher maximum fracture loads than fixation with cannulated screws. Materials and Methods. 12 matched paired fresh frozen tibias with periprosthetic tibial plateau fractures were used for this study. In group A osteosyntheses with angle-stable plates were performed, whereas in group B cannulated screws were utilized to fixate the periprosthetic fractures. DEXA bone density measurement and standard X-rays (ap and lateral) were accomplished before loading the tibias under standardised conditions with a maximum load of up to 10.0kN. Results. In the plate group all tibias fractured with a median load of Fmax=2.64 (0.45–5.68) kN, whereas in the group with cannulated screws fractures occurred at a mean load of Fmax=1.50 (0.27–3.51) kN. The difference was statistically significant with p<0.05. Discussion. Angle-stable plates showed significantly higher fracture load resistance than fixation with cannulated screws. Therefore osteosynthesis with angle-stable plates in periprosthetic tibial plateau fractures should be recommended. MULTIPLE DISCLOSURES


The Journal of Bone & Joint Surgery British Volume
Vol. 91-B, Issue 8 | Pages 1100 - 1102
1 Aug 2009
Kutty S Pettit P Powell JN

Fracture of the neck of the femur after resurfacing arthroplasty usually leads to failure and conversion to a total hip replacement. We describe an intracapsular fracture of the femoral neck sustained after hip resurfacing which was treated by cannulated screws, resulting in union and retention of the resurfacing implant. The result at follow-up three years later was very satisfactory with a Harris hip score of 99


Bone & Joint Open
Vol. 3, Issue 3 | Pages 182 - 188
1 Mar 2022
Boktor J Badurudeen A Rijab Agha M Lewis PM Roberts G Hills R Johansen A White S

Aims. In UK there are around 76,000 hip fractures occur each year 10% to 15% of which are undisplaced intracapsular. There is considerable debate whether internal fixation is the most appropriate treatment for undisplaced fractures in older patients. This study describes cannulated hip screws survivorship analysis for patients aged ≥ 60 years with undisplaced intra-capsular fractures. Methods. This was a retrospective cohort study of consecutive patients aged ≥ 60 years who had cannulated screws fixation for Garden I and II fractures in a teaching hospital between March 2013 and March 2016. The primary outcome was further same-side hip surgery. Descriptive statistics were used and Kaplan-Meier estimates calculated for implant survival. Results. A total of 114 operations were performed on 112 patients with a mean age of 80.2 years (SD 8.9). The 30-day and one-year mortality were 1% (n = 1) and 13% (n = 15), respectively. Median follow-up was 6.6 years (interquartile range 6.0 to 7.3). Kaplan-Meier estimates showed a survivorship of 95% at one year and 90% at five years (95% confidence interval 84% to 95%) for cannulated screws. Nine patients underwent further hip surgery: four revision to total hip arthroplasty, one revision to hemiarthroplasty, three removals of screws, and one haematoma washout. Posterior tilt was assessable in 106 patients; subsequent surgery was required in two of the six patients identified with a posterior angle > 20° (p = 0.035 vs angle < 20°). Of the 100 patients with angle < 20°, five-year survivorship was 91%, with seven patients requiring further surgery. Conclusion. This study of cannulated hip screw fixation for undisplaced fractures in patients aged ≥ 60 years reveals a construct survivorship without further operation of 90% at five years. Cannulated screws can be considered a safe reliable treatment option for Garden I and II fractures. Caution should be taken if posterior tilt angle on lateral view exceeds 20°, due to a higher failure rate and reoperation, and considered for similar management to Garden III and IV injuries. Cite this article: Bone Jt Open 2022;3(3):182–188


Bone & Joint Open
Vol. 5, Issue 2 | Pages 87 - 93
2 Feb 2024
Wolf O Ghukasyan Lakic T Ljungdahl J Sundkvist J Möller M Rogmark C Mukka S Hailer NP

Aims. Our primary aim was to assess reoperation-free survival at one year after the index injury in patients aged ≥ 75 years treated with internal fixation (IF) or arthroplasty for undisplaced femoral neck fractures (uFNFs). Secondary outcomes were reoperations and mortality analyzed separately. Methods. We retrieved data on all patients aged ≥ 75 years with an uFNF registered in the Swedish Fracture Register from 2011 to 2018. The database was linked to the Swedish Arthroplasty Register and the National Patient Register to obtain information on comorbidity, mortality, and reoperations. Our primary outcome, reoperation, or death at one year was analyzed using restricted mean survival time, which gives the mean time to either event for each group separately. Results. Overall, 3,909 patients presenting with uFNFs were included. Of these patients, 3,604 were treated with IF and 305 with primary arthroplasty. There were no relevant differences in age, sex, or comorbidities between groups. In the IF group 58% received cannulated screws and 39% hook pins. In the arthroplasty group 81% were treated with hemiarthroplasty and 19% with total hip arthroplasty. At one year, 32% were dead or had been reoperated in both groups. The reoperation-free survival time over one year of follow-up was 288 days (95% confidence interval (CI) 284 to 292) in the IF group and 279 days (95% CI 264 to 295) in the arthroplasty group, with p = 0.305 for the difference. Mortality was 26% in the IF group and 31% in the arthroplasty group at one year. Reoperation rates were 7.1% in the IF group and 2.3% in the arthroplasty group. Conclusion. In older patients with a uFNF, reoperation-free survival at one year seems similar, regardless of whether IF or arthroplasty is the primary surgery. However, this comparison depends on the choice of follow-up time in that reoperations were more common after IF. In contrast, we found more early deaths after arthroplasty. Our study calls for a randomized trial comparing these two methods. Cite this article: Bone Jt Open 2024;5(2):86–92


We evaluated the outcome of treatment of nonunion of an intracapsular fracture of the femoral neck in young patients using two cannulated screws and a vascularised bone graft. A total of 32 patients (15 women and 17 men, with a mean age of 36.5 years; 20 to 50) with failed internal fixation of an intracapsular fracture were included in the study. Following removal of the primary fixation, two cannulated compression screws were inserted with a vascularised iliac crest bone graft based on the ascending branch of the lateral femoral circumflex artery. At a mean follow-up of 6.8 years (4 to 10), union was achieved in 27 hips (84%). A total of five patients with a mean age of 40.5 years (35 to 50) had a persistent nonunion and underwent total hip arthroplasty as also did two patients whose fracture united but who developed osteonecrosis of the femoral head two years post-operatively. Statistical analysis showed that younger patients achieved earlier and more reliable union (p < 0.001). The functional outcome, as assessed by the Harris Hip score, was better in patients aged < 45 years compared with those aged > 45 years (p < 0.001). . These findings suggest that further fixation using two cannulated compression screws and a vascularised iliac crest bone graft is an effective salvage treatment in patients aged <  45 years, in whom osteosynthesis of a displaced intracapsular fractures of the femoral neck has failed. Cite this article: Bone Joint J 2015; 97-B:988–91


There is a high risk of the development of avascular necrosis of the femoral head and nonunion after the treatment of displaced subcapital fractures of the femoral neck in patients aged < 50 years. We retrospectively analysed the results following fixation with two cannulated compression screws and a vascularised iliac bone graft. We treated 18 women and 16 men with a mean age of 38.5 years (20 to 50) whose treatment included the use of an iliac bone graft based on the ascending branch of lateral femoral circumflex artery. There were 20 Garden grade III and 14 grade IV fractures. Clinical and radiological outcomes were evaluated. The mean follow-up was 5.4 years (2 to 10). In 30 hips (88%) union was achieved at a mean of 4.4 months (4 to 6). Nonunion occurred in four hips (12%) and these patients had a mean age of 46.5 years (42 to 50) and underwent revision to a hip replacement six months after operation. The time to union was dependent on age with younger patients achieving earlier union (p < 0.001). According to the Harris hip score which was available for 27 of the 30 hips with satisfactory union, excellent results were obtained in 15 (score ≥ 90 points), fair in ten (score 80 to 90 points), and poor in two hips (≤ 80 points). One patient aged 48 years developed avascular necrosis of femoral head six years after operation and underwent total hip replacement. The management of displaced subcapital fractures of the femoral neck, in patients aged <  50 years, with two cannulated compression screws and an iliac bone graft based on the ascending branch of lateral femoral circumflex artery, gives satisfactory results with a low rate of complication including avascular necrosis and nonunion. Cite this article: Bone Joint J 2014;96-B:1024–8


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_11 | Pages 35 - 35
1 Dec 2020
Scattergood SD Berry AL Flannery O Fletcher JWA Mitchell SR
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Intracapsular neck of femur fractures may be treated with fixation or arthroplasty, depending on fracture characteristics and patient factors. Two common methods of fixation are the sliding hip screw, with or without a de-rotation screw, and cannulated screws. Each has its merits, and to date there is controversy around which method is superior, with either method thought to risk avascular necrosis of the femoral head (AVN) rates in the region of 10–20%. Fixation with cannulated screws may be performed in various ways, with current paucity of evidence to show an optimum technique. There are a multitude of factors which are likely to affect patient outcomes: technique, screw configuration, fracture characteristics and patient factors. We present a retrospective case series analysis of 65 patients who underwent cannulated screw fixation of a hip fracture. Electronic operative records were searched from July 2014 until July 2019 for all patients with a neck of femur fracture fixed with cannulated screws: 68 were found. Three patients were excluded on the basis of them having a pathological fracture secondary to malignancy, cases were followed up for 2 years post-operatively. Electronic patient records and X-rays were reviewed for all included patients. All X-rays were examined by each team member twice, with a time interval of two weeks to improve inter-observer reliability. 65 patients were included with 2:1 female to male ratio and average age of 72 years. 36 patients sustained displaced fractures and 29 undisplaced. Ten patients sustained a high-energy injury, none of which developed AVN. Average time to surgery was 40 hours and 57 patients mobilised on day one post-operatively. All cases used either 7 or 7.3mm partially threaded screws in the following configurations: 2 in triangle apex superior, 39 triangle apex inferior, 22 rhomboid and 2 other, with 9 cases using washers. All reductions were performed closed. Five (8%) of our patients were lost to follow-up as they moved out of area, 48 (74%) had no surgical complications, seven (11%) had mild complications, three (5%) moderate and two (3%) developed AVN. Both of these sustained displaced fractures with low mechanism of injury, were female, ASA 2 and both ex-smokers. One received three screws in apex inferior configuration and one rhomboid, neither fixed with washers. Our AVN rate following intracapsular hip fracture fixation with cannulated screws is much lower than widely accepted. This study is under-powered to comment on factors which may contribute to the development of AVN. However, we can confidently say that our practice has led to low rates of AVN. This may be due to our method of fixation; we use three screws in an apex inferior triangle or four screws in a rhomboid, our consultant-led operations, closed reduction of all fractures, or our operative technique. We pass a short thread cannulated screw across the least comminuted aspect of the fracture first in order to achieve compression, followed by two or three more screws (depending on individual anatomy) to form a stable construct. Our series shows that fixation of intracapsular hip fractures with cannulated screws as we have outlined remains an excellent option. Patients retain their native hip, have a low rate of AVN, and avoid the risks of open reduction


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_17 | Pages 41 - 41
24 Nov 2023
Lilleøre JG Jørgensen A Knudsen M Hanberg P Öbrink-Hansen K Tøstesen S Søballe K Stilling M Bue M
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Background and aim. Implant-associated osteomyelitis is one of the most feared complications following orthopedic surgery. Although the risk is low it is crucial to achieve adequate antibiotic concentrations proximate to the implant for a sufficient amount of time to protect the implant surface and ensure tissue integration. The aim of this study was to assess steady-state piperacillin concentrations in the proximity of an orthopedic implant inserted in cancellous bone. Method. Six female pigs received an intravenous bolus infusion of 4 g/0.5 g piperacillin/tazobactam over 30 min every 6 h. Steady state was assumed achieved in the third dosing interval (12–18 h). Microdialysis catheters were placed in a cannulated screw in the proximal tibial cancellous bone, in cancellous bone next to the screw, and in cancellous bone on the contralateral tibia. Dialysates were collected from time 12 to 18 h and plasma samples were collected as reference. Results. Time above the minimal inhibitory concentration (fT>MIC) was evaluated for MIC of 8 (low target) and 16 μg/mL (high target). For the low piperacillin target (8 μg/mL), comparable mean fT>MIC across all the investigated compartments (mean range: 54–74%) was found. For the high target (16 μg/mL), fT>MIC was shorter inside the cannulated screw (mean: 16%) than in the cancellous bone next to the screw and plasma (mean range: 49–54%), and similar between the two cancellous bone compartments. Conclusions. To reach more aggressive piperacillin fT>MIC targets in relation to the implant, alternative dosing regimens such as continuous infusion may be considered


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_1 | Pages 56 - 56
2 Jan 2024
Zderic I Warner S Stoffel K Woodburn W Castle R Penman J Saura-Sanchez E Helfet D Gueorguiev B Sommer C
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Treatment of both simple and complex patella fractures is a challenging clinical problem. The aim of this study was to investigate the biomechanical performance of recently developed lateral rim variable angle locking plates versus tension band wiring used for fixation of simple and complex patella fractures. Twelve pairs of human anatomical knees were used to simulate either two-part transverse simple AO/OTA 34C1 or five-part complex AO/OTA 34C3 patella fractures by means of osteotomies, with each fracture model created in six pairs. The complex fracture pattern was characterized by a medial and a lateral proximal fragment, together with an inferomedial, an inferolateral, and an inferior fragment mimicking comminution around the distal patellar pole. The specimens with simple fractures were pairwise assigned for fixation with either tension band wiring through two parallel cannulated screws, or a lateral rim variable angle locking plate. The knees with complex fractures were pairwise treated with either tension band wiring through two parallel cannulated screws plus circumferential cerclage wiring, or a lateral rim variable angle locking plate. Each specimen was tested over 5000 cycles by pulling on the quadriceps tendon, simulating active knee extension and passive knee flexion within the range of 90° flexion to full knee extension. Interfragmentary movements were captured via motion tracking. For both fracture types, the longitudinal and shear articular displacements measured between the proximal and distal fragments at the central patella aspect between 1000 and 5000 cycles, together with the relative rotations of these fragments around the mediolateral axis were all significantly smaller following the lateral rim variable angle locked plating compared with tension band wiring, p<0.01. Lateral rim locked plating of both simple and complex patella fractures provides superior construct stability versus tension band wiring under dynamic loading


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_7 | Pages 23 - 23
4 Apr 2023
Stoffel K Zderic I Pastor T Woodburn W Castle R Penman J Saura-Sanchez E Gueorguiev B Sommer C
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Treatment of simple and complex patella fractures represents a challenging clinical problem. Controversy exists regarding the most appropriate fixation method. Tension band wiring, aiming to convert the pulling forces on the anterior aspect of the patella into compression forces across the fracture site, is the standard of care, however, it is associated with high complication rates. Recently, anterior variable-angle locking plates have been developed for treatment of simple and comminuted patella fractures. The aim of this study was to investigate the biomechanical performance of the novel anterior variable-angle locking plates versus tension band wiring used for fixation of simple and complex patella fractures. Sixteen pairs of human cadaveric knees were used to simulate either two-part transverse simple AO/OTA 34-C1 or five-part complex AO/OTA 34-C3 patella fractures by means of osteotomies, with each fracture model created in eight pairs. The complex fracture pattern was characterized with a medial and a lateral proximal fragment, together with an inferomedial, an inferolateral and an inferior fragment mimicking comminution around the distal patellar pole. The specimens with simple fractures were pairwise assigned for fixation with either tension band wiring through two parallel cannulated screws, or an anterior variable-angle locking core plate. The knees with complex fractures were pairwise treated with either tension band wiring through two parallel cannulated screws plus circumferential cerclage wiring, or an anterior variable-angle locking three-hole plate. Each specimen was tested over 5000 cycles by pulling on the quadriceps tendon, simulating active knee extension and passive knee flexion within the range from 90° flexion to full knee extension. Interfragmentary movements were captured by motion tracking. For both fracture types, the articular displacements, measured between the proximal and distal fragments at the central aspect of the patella between 1000 and 5000 cycles, together with the relative rotations of these fragments around the mediolateral axis were all significantly smaller following the anterior variable-angle locked plating compared with the tension band wiring, p < 0.01. From a biomechanical perspective, anterior locked plating of both simple and complex patella fractures provides superior construct stability versus tension band wiring


The Bone & Joint Journal
Vol. 101-B, Issue 9 | Pages 1160 - 1167
1 Sep 2019
Wang WT Li YQ Guo YM Li M Mei HB Shao JF Xiong Z Li J Canavese F Chen SY

Aims. The aim of this study was to clarify the factors that predict the development of avascular necrosis (AVN) of the femoral head in children with a fracture of the femoral neck. Patients and Methods. We retrospectively reviewed 239 children with a mean age of 10.0 years (. sd. 3.9) who underwent surgical treatment for a femoral neck fracture. Risk factors were recorded, including age, sex, laterality, mechanism of injury, initial displacement, the type of fracture, the time to reduction, and the method and quality of reduction. AVN of the femoral head was assessed on radiographs. Logistic regression analysis was used to evaluate the independent risk factors for AVN. Chi-squared tests and Student’s t-tests were used for subgroup analyses to determine the risk factors for AVN. Results. We found that age (p = 0.006) and initial displacement (p = 0.001) were significant independent risk factors. Receiver operating characteristic (ROC) curve analysis indicated that 12 years of age was the cut-off for increasing the rate of AVN. Severe initial displacement (p = 0.021) and poor quality of reduction (p = 0.022) significantly increased the rate of AVN in patients aged 12 years or greater, while in those aged less than 12 years, the rate of AVN significantly increased only with initial displacement (p = 0.048). A poor reduction significantly increased the rate of AVN in patients treated by closed reduction (p = 0.026); screw and plate fixation was preferable to cannulated screw or Kirschner wire (K-wire) fixation for decreasing the rate of AVN in patients treated by open reduction (p = 0.034). Conclusion. The rate of AVN increases with age, especially in patients aged 12 years or greater, and with the severity of displacement. In patients treated by closed reduction, anatomical reduction helps to decrease the rate of AVN, while in those treated by open reduction, screw and plate fixation was preferable to fixation using cannulated screws or K-wires. Cite this article: Bone Joint J 2019;101-B:1160–1167


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_2 | Pages 70 - 70
1 Mar 2021
Scattergood S Flannery O Berry A Fletcher J Mitchell S
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Abstract. Objectives. The use of cannulated screws for femoral neck fractures is often limited by concerns of avascular necrosis (AVN) occurring, historically seen in 10–20% of fixed intracapsular fractures. The aim of this study was to investigate the rate of AVN with current surgical techniques within our unit. Methods. A single centre retrospective review was performed. Operative records between 1st July 2014 and 31st May 2019 were manually searched for patients with an intracapsular neck of femur fracture fixed with cannulated screws, with minimum one year follow up. Patient records and radiographs were reviewed for clinical and radiographic diagnoses of AVN and/or non-union. Fracture pattern and displacement, screw configuration and reduction techniques were recorded, with radiographs independently analysed by five orthopaedic surgeons. Results. Sixty-five patients were identified, average age of 72 years (range 48–87). Thirty-six patients (55%) sustained displaced fractures and 29 patients (45%) had undisplaced fractures. Two (3%) patients developed AVN, with no cases of fracture non-union. Ten patients (15%) sustained a high-energy injury, though none of these patients developed AVN. Screws configurations were: two (3%) triangle apex-superior, 39 (60%) triangle apex-inferior, 22 (34%) rhomboid and two (3%) other, with nine (14%) cases using washers. All fractures required closed reduction; no open reductions performed. Conclusions. Our observed AVN rate is much lower than widely reported, especially given the proportion of displaced fractures that were fixed. With adequate fixation, even in displaced fracture patterns with imperfect reduction, cannulated screws are an excellent option for intracapsular neck of femur fractures. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_7 | Pages 5 - 5
4 Apr 2023
Vicary-Watts R McLauchlan G
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Cannulated hip screws are frequently used in the management of hip fractures. There have been concerns over the failure rate of the technique and the outcomes of those that subsequently require conversion to total hip replacement (THR). This study utilised a database of over 600 cannulated hip screw (CHS) fixations performed over a 14-year period and followed up for a minimum of one year (1-14). We identified 57 cases where a conversion to THR took place (40 females, 17 males, mean age: 71.2 years). Patient demographics, original mechanism of injury, fracture classification, reason for fixation failure, time until arthroplasty, implant type and post-arthroplasty complications were recorded. Clinical outcomes were measured using the Oxford Hip Score. The failure rate of cannulated screw treatment was 9.4% and the mean time from initial fixation to arthroplasty was 15.4 (16.5) months. Thirty six fractures were initially undisplaced and 21 were displaced. As one might expect the displaced cases tended to be younger but this didn't reach statistical significance [66.5(14.3) vs 72.7(13.1), p=0.1]. The commonest causes of failure were non-union (25 cases, 44%) and avascular necrosis (17 cases, 30%). Complications after THR consisted of one leg length discrepancy and one peri-prosthetic fracture. The mean Oxford score pre-arthroplasty was 12.2 (8.4), improving to 38.4 (11.1) at one-year. Although the pre op Oxford scores tended to be lower in patients with undisplaced fractures and higher ASA scores, the improvement was the same whatever the pre-op situation. The one-year Oxford score and the improvement in score are comparable to those seen in the literature for THR in general. In conclusion, CHS has a high success rate and where salvage arthroplasty is required it can provide good clinical outcomes with low complication rates


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_6 | Pages 66 - 66
1 Apr 2018
Chang C Yang C Chen Y Chang C
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For the management of displaced patellar fractures, surgical fixation using cannulated screws along with anterior tension band wiring is getting popular. Clinical and biomechanical studies have reported that using cannulated screws and a wire instead of the modified tension band with Kirschner wires improves the stability of fractured patellae. However, the biomechanical effect of screw proximity on the fixed construction remains unclear. The aim of this study was to evaluate the mechanical behaviors of the fractured patella fixed with two cannulated screws and tension band at different depths of the patella using finite element method. A patella model with simple transverse fracture [AO 34-C1] was developed; the surgical fixation consisted of two 4.0-mm parallel partial-threaded cannulated screws with a figure-of-eight anterior tension band wiring using a 1.25-mm stainless steel cable. Two different locations, including the screws 5-mm and 10-mm away from the leading edge of the patella, were used. A tension force of 850 N was applied on the patellar apexes at two loading angles (45° and 0° [parallel] to the long axis) to simulate different loading conditions while knee ambulation. The proximal side (base) of the patella was fixed, and the inferior articular surface was defined as a compression-only support in ANSYS to simulate the support from distal femur condyles. Compression-only support enables the articular surfaces of the present patella to only bear compression and no tension forces. Under different loading conditions, the fixed fractured patella yielded higher stability during 0° loading of tension force than during 45° loading. When the screws were parallel placed at the depth of 5 mm away from the patellar surface, the deformation of patellar fragment and maximum gap opening at the fracture site were smaller than those obtained by screws placed at the depth of 10 mm away from the patellar surface. Compared to the superficial screw placement, the deeper placement (10 mm) increased the maximum gap opening at the fracture site by 1.56 times under 45° loading, and 1.58 times under 0° loading. The load on the tension band wire of the 10-mm screw placement was 3.12 times (from 230 to 717 N) higher than that of the 5-mm placement. Under the wire, the contact pressure on the patellar surface was higher with the 10-mm screw placement than the 5-mm screw placement. The peak bone contact pressures with the 10-mm placement were 7.7 times (99.5 to 764 MPa) higher. This is the first numerical study to examine the biomechanical effects of different screw locations on the fixation of a fractured patella using screws and tension band. Based on a higher stability and lower cable tension obtained by the superficial screws placement, the authors recommended the superficial screw placement (5 mm below the leading edge of the patella) rather than the deep screws while fixing the transverse patellar fracture with cannulated screws and cable


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_IV | Pages 553 - 553
1 Oct 2010
Mcgrath A Iain S Katevu K Torrie A
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Hip fracture is a common serious injury in the elderly. Between 1982 and 1998 the number of hip fractures reported annually in Scotland in patients over 55 years rose from 4,000 to 5,700. The optimum method of treatment for the various fracture types remains in contention. We compare outcome measures between displaced, intracapsular fractures in patients over 70 years fixed with cannulated screws and sliding hip screw with side plate. Between 1998 and 2005 a total of 30,482 patients were reviewed by the Scottish Hip Fracture Audit (SHFA). Of these 15,823(53.3% of the total) had sustained intracapsular fractures. 13,587 of these occurred in patients aged 70 or over. Of these 2,428 had undisplaced and 11,159 displaced fractures. Chi test statistical analysis compare outcome measures in this group of displaced intracapsular fractures with respect to aspects of early failure. 534(3.9%) of patients were treated conservatively. 509 (4.7%) fractures were fixed using cannulated screws and 499 (4.6%) using a sliding hip screw. Readmission within 120 days for any cause occurred in 62 patients(14.1%) treated with cannulated screw fixation and in 63 patients(15.7%) for those treated with a sliding hip screw(P=0.509). Of these 36 patients(8.2%) in the former and 23 patients(5.7%) in the latter group were readmitted for complications related to hip fracture(P=0.033). Mortality within this period included 69 patients(13.5%) in the CS and 98(19.6%) in the SHS group. In terms of re-operation within 120 days of the original admission, 53 patients(10.6%) receiving cannulated screws compared to 24 patients(4.8%) treated with a sliding hip screw requiring further surgery(P=0.0006). The fracture was seen to displace in 12(22.6%) patients originally treated with cannulated screws compared to 6 patients(25%) treated with sliding hip screw(P=0.156). More significantly the fixation device was seen to have migrated in 24(45.3%) of the cannulated screw as compared to 7(29.2%) patients in the sliding hip screw group(P=0.002). Periprosthetic fractures were recorded in 4(7.5%) of the former and 3(12.5%) in the latter group(P=0.708). Wound infection was higher in the SHS group(2 patients) as compared to the screw fixation group(1 patient)(P=0.565). Statistical analysis demonstrates a dramatic difference exists between these 2 fixation types in terms of re-operation within 120 days of the original admission for which published literature has previously only recorded biomechanical, in vitro comparisons. Data regarding specific implant factors such as number of screws, position, configuration, starting point, thread length and use of washers in cannulated screws, and position, tapping, supplementary screw and compression screw in sliding hip screws was not recorded and may be considered to bias our results


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_II | Pages 357 - 358
1 May 2010
McGrath A Johnstone A
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Hip fracture is a common serious injury in the elderly. Between 1982 and 1998 the number of hip fractures reported annually in Scotland in patients over 55 years rose from 4,000 to 5,700. The optimum method of treatment for the various fracture types remains in contention. The purpose of this study was to compare outcome measures between displaced, intracapsular fractures in patients over 70 years fixed with cannulated screws and sliding hip screw with side plate. Between 1998 and 2005 a total of 30,482 patients were reviewed by the Scottish Hip Fracture Audit (SHFA). Of these 15,823(53.3% of the total) had sustained intracapsular fractures. 13,587 of these occurred in patients aged 70 or over. Of these 2,428 had undisplaced and 11,159 displaced fractures. We performed a Chi test statistical analysis comparing outcome measures in this group of displaced intracapsular fractures with respect to aspects of early failure. 534(3.9%) of patients were treated conservatively. 509 (4.7%) fractures were fixed using cannulated screws and 499 (4.6%) using a sliding hip screw. Readmission within 120 days for any cause occurred in 62 patients(14.1%) treated with cannulated screw fixation and in 63 patients(15.7%) for those treated with a sliding hip screw(P=0.509). Of these 36 patients(8.2%) in the former and 23 patients(5.7%) in the latter group were readmitted for complications related to hip fracture(P=0.033). Mortality within this period included 69 patients(13.5%) in the CS and 98(19.6%) in the SHS group. In terms of re-operation within 120 days of the original admission, 53 patients(10.6%) receiving cannulated screws compared to 24 patients(4.8%) treated with a sliding hip screw requiring further surgery(P=0.0006). The fracture was seen to displace in 12(22.6%) patients originally treated with cannulated screws compared to 6 patients(25%) treated with sliding hip screw(P=0.156). More significantly the fixation device was seen to have migrated in 24(45.3%) of the cannulated screw as compared to 7(29.2%) patients in the sliding hip screw group(P=0.002). Periprosthetic fractures were recorded in 4(7.5%) of the former and 3(12.5%) in the latter group(P=0.708). Wound infection was higher in the SHS group(2 patients) as compared to the screw fixation group(1 patient)(P=0.565). Statistical analysis demonstrates a dramatic difference exists between these 2 fixation types in terms of re-operation within 120 days of the original admission for which published literature has previously only recorded biomechanical, in vitro comparisons. Data regarding specific implant factors such as number of screws, position, configuration, starting point, thread length and use of washers in cannulated screws, and position, tapping, supplementary screw and compression screw in sliding hip screws was not recorded and may be considered to bias our results


The Journal of Bone & Joint Surgery British Volume
Vol. 91-B, Issue 8 | Pages 1078 - 1082
1 Aug 2009
Kang HG Roh YW Kim HS

We have developed a hollow perforated cannulated screw. One or more of these was implanted percutaneously in 11 patients with an osteolytic metastasis in the femoral neck and multiple metastases elsewhere. They were supplemented by one or two additional standard 6.5 mm cannulated screws in nine patients. Polymethylmethacrylate bone cement was injected through the screw into the neck of the femur using small syringes, as in vertebroplasty. The mean amount of cement injected was 23.2 ml (17 to 30). Radiotherapy was started on the fourth post-operative day and chemotherapy, on average, was resumed a day later. Good structural stability and satisfactory relief from pain were achieved in all the patients. This technique may be useful in the palliation of metastases in the femoral neck


Bone & Joint Research
Vol. 9, Issue 6 | Pages 314 - 321
1 Jun 2020
Bliven E Sandriesser S Augat P von Rüden C Hackl S

Aims. Evaluate if treating an unstable femoral neck fracture with a locking plate and spring-loaded telescoping screw system would improve construct stability compared to gold standard treatment methods. Methods. A 31B2 Pauwels’ type III osteotomy with additional posterior wedge was cut into 30 fresh-frozen femur cadavers implanted with either: three cannulated screws in an inverted triangle configuration (CS), a sliding hip screw and anti-rotation screw (SHS), or a locking plate system with spring-loaded telescoping screws (LP). Dynamic cyclic compressive testing representative of walking with increasing weight-bearing was applied until failure was observed. Loss of fracture reduction was recorded using a high-resolution optical motion tracking system. Results. LP constructs demonstrated the highest mean values for initial stiffness and failure load. LP and SHS constructs survived on mean over 50% more cycles and to loads 450 N higher than CS. During the early stages of cyclic loading, mean varus collapse of the femoral head was 0.5° (SD 0.8°) for LP, 0.7° (SD 0.7°) for SHS, and 1.9° (SD 2.3°) for CS (p = 0.071). At 30,000 cycles (1,050 N) mean femoral neck shortening was 1.8 mm (SD 1.9) for LP, 2.0 mm (SD 0.9) for SHS, and 3.2 mm (SD 2.5) for CS (p = 0.262). Mean leg shortening at construct failure was 4.9 mm (SD 2.7) for LP, 8.9 mm (SD 3.2) for SHS, and 7.0 mm (SD 4.3) for CS (p = 0.046). Conclusion. Use of the LP system provided similar (hip screw) or better (cannulated screws) biomechanical performance as the current gold standard methods suggesting that the LP system could be a promising alternative for the treatment of unstable fractures of the femoral neck. Cite this article: Bone Joint Res 2020;9(6):314–321


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_I | Pages 79 - 79
1 Mar 2009
Kelley S Rogers M Morgan B Jackson M
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INTRODUCTION – Tuberosity fractures of the calcaneum are rare injuries. The traditional operative treatment involves open reduction and internal fixation with a tension band wire construct. We have developed a new technique of fixing these fractures with internal fixation using cannulated screws and a figure of eight wire. This paper describes the new technique outlining its advantages and compares the 2 methods of fixation biomechanically to determine their properties with respect to fracture fixation. METHOD – 20 sections of bovine bone were taken to act as an experimental model for the calcaneum. They were osteotomised to create the posterior process fracture model. 10 were fixed using a traditional tension band wire construct and 10 were fixed using the cannulated screw and wire construct. Each construct was subjected to biomechanical testing to identify the stiffness, energy to failure and load to failure. RESULTS – During loading the cannulated screw and wire constructs showed a significant increase in stiffness and energy to failure compared to the tension band wire constructs. CONCLUSION – The increased stability of the cannulated screw construct demonstrated by the testing offers biomechanical benefit over the traditional tension band wire construct. This, as well as the improved technical aspects of the cannulated screw fixation, may be beneficial for clinical use