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The Journal of Bone & Joint Surgery British Volume
Vol. 87-B, Issue 4 | Pages 556 - 559
1 Apr 2005
Al-Maiyah M Bajwa A Finn P Mackenney P Hill D Port A Gregg PJ

We conducted a randomised, controlled trial to determine whether changing gloves at specified intervals can reduce the incidence of glove perforation and contamination in total hip arthroplasty. A total of 50 patients were included in the study. In the study group (25 patients), gloves were changed at 20-minute intervals or prior to cementation. In the control group (25 patients), gloves were changed prior to cementation. In addition, gloves were changed in both groups whenever there was a visible puncture. Only outer gloves were investigated. Contamination was tested by impression of gloved fingers on blood agar and culture plates were subsequently incubated at 37°C for 48 hours. The number of colonies and types of organisms were recorded. Glove perforation was assessed using the water test. The incidence of perforation and contamination was significantly lower in the study group compared with the control group. Changing gloves at regular intervals is an effective way to decrease the incidence of glove perforation and bacterial contamination during total hip arthroplasty


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_20 | Pages 1 - 1
1 Dec 2017
Uehara M Takahashi J Ikegami S Kuraishi S Shimizu M Futatsugi T Oba H Kato H
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Pedicle screw (PS) insertion has been critised for its risk of serious injury to neurovascular structures. Although computed tomography (CT)-based navigation has been developed to avoid such complications, perforation remains an issue, even with the aid of additional guidance. We clarify screw perforation rate and direction in 359 consecutive patients treated using CT-based PS insertion and present important considerations for more accurate screw placement. The medical records of 359 consecutive patients who underwent PS insertion involving C2-L5 using a CT-based navigation system were reviewed. Postoperative CT images were analysed to evaluate the accuracy of screw placement. We investigated both rate and direction of screw perforation according to vertebral level. Of the 3413 PS that were inserted, 3.0% (104/3413) were judged as Grade 3 (more than 4mm) perforations. Allover perforation rates by vertebral level were shown in Table 1. The rate of these perforations was 5.0% for C2, 7.8% for C3–5, 3.9% for C6–7, 3.4% for T1–4, 3.5% for T5–8, 1.4% for T9–12, and 1.7% for L1–5. We also analysed the odds ratio (OR) for screw perforation in vertebrae accounting for the effects of age and disease. Multivariate analysis identified that PS insertions at C3–5 (OR 4.9, 95% CI 2.2–10.9; p<0.001) were significantly associated with Grade 3 screw perforation as compared with that of L1–5. Even with CT-based navigation, careful insertion of PS is needed in the middle cervical spine because of a significantly higher perforation rate as compared with the lumbar region. For figures and tables, please contact authors directly


The Journal of Bone & Joint Surgery British Volume
Vol. 86-B, Issue 6 | Pages 898 - 900
1 Aug 2004
Laine T Aarnio P

The spread of viral diseases such as HIV has highlighted the importance of protecting medical personnel against contamination from blood. We have assessed the frequency of the perforation of surgical gloves during orthopaedic and trauma surgery and compared the efficiency of single and double gloving. We examined all the gloves used by surgeons for a period of two months. There were 1769 gloves from 349 operations. Perforations occurred in 18.5% of conventional and 5.8% of arthroscopic procedures. The risk of contamination from blood was 13 times higher when using single compared with double gloves. Surprisingly, the combination of two regular gloves was much less efficient than double indicator gloves when comparing the rate of perforation of the inner glove when the outer had been damaged (24% vs 4.9%; p = 0.02). We recommend double gloving in orthopaedic surgery in general and also in long arthroscopic procedures


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_16 | Pages 48 - 48
1 Oct 2014
Ren H Wong K Feng C Yang Z
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In orthopedic surgeries, it is critical to reduce the risks of drilling complications during bone fracture fixation, especially around critical organs such as in acetabula-pelvic procedures. Either over-drilling or x-ray overuse shall be avoided to reduce potential complications to the surrounding critical organs or tissues. Toward recognising perforation process during bong drilling, we employed drilling vibration signal analysis based on the measurements from miniature inertial sensors. Time-frequency analysis is used for features extractions, which show that information from drilling vibration measurements could reveal the drilling process, hence help doctors track the drilling process and avoid over-drilling. We addressed the aforementioned challenges through inertial sensor development, vibration measurements, and time-frequency signal analysis. In the preliminary ex-vivo bone drilling experiment setup, an inertial sensor is mounted on a pig femur bone with two fixing nails and can capture 3-axes acceleration data during drilling procedures. A cordless drill is used with Kirschner wires (K-wires) and the diameter of the pin is 3.5 mm. The mounting locations of inertial sensors are close to actual drilling entries without affecting normal procedures. The recorded vibration signals indicate how the drill is interacting with surrounding bone tissues, which shall have different patterns along the deep drilling process. After normalisation, the power spectral density (PSD) is calculated to examine the frequency domain representation of the time series during drilling process. As the drilling vibration process along the bone is non-stationary, we further employ wavelet transform for more localised time-frequency analysis. When the bone substance interacts with drill bits, compact substance and spongy substance have different bone densities and structures, thus inducing different vibration waveform patterns. In our preliminary experiments, we recorded acceleration data from the pig femur drilling process, where a surgical drill penetrates from compact substance, spongy substance and then to compact substance again. The article shows the feasibility study of estimating femur bone drilling process based on vibrations signals captured from low-cost miniature inertial sensors. Through a preliminary animal ex-vivo bone study, the proposed framework of time-frequency wavelet analysis indicates the drilling interface between compact substance and spongy substance. It shows potentials in perforation recognition along drilling process and more clinical studies will be performed for validating its capability in over-drilling avoidance


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_5 | Pages 131 - 131
1 Mar 2017
Sadeghi M Mirghasemi S Rashidinia S Gabaran N Talebizadeh M Eftekhari S
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Objectives. Despite promising results have shown by osteogenic cell-based demineralized bone matrix composites, they need to be optimized for grafts that act as structural frameworks in load-bearing defects. The aims of this study is attempt to assess the effects of laser perforations on osteoinduction in cortical bone allografts. Methods. Sixteen wistar rats were divided into two groups according to the type of structural bone allograft; the first: partially demineralized only (Donly) and the second: partially demineralized laser-perforated (DLP). Trans-cortical holes were achieved by Er:YAG laser at a wave length of 2.94 µm in four rows of three holes approximated cylindrical holes 0.5 mm in diameter, with centres 2.5 mm apart. Histologic and histomorphometric analysis were performed at 12 weeks. Results. Statistical analysis showed significant differences between the 2 groups at 3 months. Results showed that partially demineralized laser-perforated grafts had substantially higher incorporation by woven bone than partially demineralized grafts; yet this difference at the interface gap remained insignificant. In DLP allografts healing at the junction was more complete and a wider area was in contact with host and graft surfaces. Conclusions. Based on the results of this study, it may be concluded that surface changes induced by Er:YAG laser, accelerated bone healing with good osteoinduction results and the process might have improved, if they could have been supplemented with the proper stipulations


Long femoral nails for neck of femur fractures and prophylactic fixation have a risk of anterior cortex perforation. Previous studies have demonstrated the radius of curvature (ROC) of a femoral nail influencing the finishing point of a nail and the risk of anterior cortex perforation. This study aims to calculate a patients femoral ROC using preoperative XR and CT and therefore nail finishing position. We conducted a retrospective study review of patients with long femoral cephalomedullary nailing for proximal femur fractures (OTA/AO 31(A) and OTA/AO 32) or impending pathological fractures at a level 1 trauma centre between January 1, 2015 and December 31, 2020 with both full length lateral X-ray and CT imaging. Femoral ROC was calculated on both imaging modalities. Outcomes measured including nail finishing position, anterior cortex encroachment and impingement. The mean femoral ROC was 1026mm on CT and 1244mm on XR. CT femoral ROC strongly correlated with nail finishing point with a spearmans coefficient of 0.77. Additionally, femurs with a ROC <1000mm were associated with a higher risk of anterior encroachment (OR 6.12) and femurs with a ROC <900mm were associated with a higher risk of anterior cortex impingement (OR 6.47). To our knowledge this is the first study to compare a measured femoral ROC to nail finishing position. The use of CT to measure femoral ROC and to a lesser extent XR was able to predict both nail finishing position and risk of anterior cortex encroachment. Preoperative XRs and CTs were able to identify patients with a small femoral ROC. This predicted patients at risk of anterior cortex impingement, anterior cortex encroachment and nail finishing position. We may be able to select femoral nails that resemble the native femoral ROC and mitigate the risk of anterior cortex perforation


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_19 | Pages 29 - 29
22 Nov 2024
Trebše N Blas M Kanalec T Angelini K Filipič T Levašic V Trebse R
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Aim. There is limited data on the frequency and impact of untoward events such as glove perforation, contamination of the surgical field (drape perforation, laceration, detachment), the unsterile object in the surgical field (hair, sweat droplet…), defecation, elevated air temperature…that may happen in the operating theatre. These events should influence the surgical site infection rate but it is not clear to what extent. We wanted to calculate the frequency and measure the impact of these events on the infection and general revision rate. Method. In our institution, scrub nurses prospectively and diligently record untoward events in the theatres. We have an institutional implant registry with close to 100% data completion since 2001, and surgeons register complications before discharge. We analysed the respective databases and compared the revision and infection rate in the group with untoward events with the outcome of all arthroplasty patients within the same period. Two-tailed Z statistical test was used for analysis. Results. Between 1.1.2012 and 31.12.2018 we operated 13574 prosthetic joints: 6232 primary THR (total hip replacement) and 5466 primary KR (total and partial knee replacement) and 1245 and 631 revisions respectively. During this period, we recorded 372 events (2.74%) including 20 (0.15 %) defecations, 40 (0.29 %) unsterile object in the surgical field, 73 (0.54%) field sterility violations, 45 (0.33 %) glove perforations, 45 (0.33 %) occasions with elevated air temperature, 106 (0.78%) with guests in the OR, 11 (0.08%) with wound near the surgical field, and 32 (0.24%) with other events. We followed the patients till 1.1.2022, in this time we recorded 27 (7.26%) reoperations in the cohort with untoward events. There were 9 (2.42%) infections and 18 (4.84%) aseptic revisions in the group with unwanted events. The infection rate for all TJR (total joint replacement) from the period 2012-2018, followed till 1.1.2022 was 2.23%, the revision rate for any reason was 4.37%. For all THR (primary and revision) the infection rate was 0.84%, the overall revision rate was 3.18% and for the KR (primary and revision) 1.71% and 5,82% respectively. The difference is significant at p>0.05 for infection rate. Conclusions. The potentially serious sterility disruptive events in the operative rooms did result in an increased infection rate but not an increase in revision rate. There is no data about the rate and the impact of these events besides for perforated surgical gloves with higher reported incidences than in our study influencing infection rate if perioperative antibiotic prophylaxis was not used. Ours is the first study reporting the impact of these unwanted events in the operating theatre. Key words. orthopaedic surgery, unwanted events, revision rate


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_6 | Pages 95 - 95
1 Jul 2020
Ayeni OR Shah A Kay J Memon M Coughlin R Simunovic N Nho SJ
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To assess the current literature on suture anchor placement for the purpose of identifying factors that lead to suture anchor perforation and techniques that reduce the likelihood of complications. Three databases (PubMed, Ovid MEDLINE, EMBASE) were searched, and two reviewers independently screened the resulting literature. Methodological quality of all included papers was assessed using Methodological Index for Non-Randomized Studies criteria and the Cochrane Risk of Bias Assessment tool. Results are presented in a narrative summary fashion using descriptive statistics. Fourteen studies were included in this review. Four case series (491 patients, 56.6% female, mean age 33.9 years), nine controlled cadaveric/laboratory studies (111 cadaveric hips and 12 sawbones, 42.2% female, mean age 60.0 years), and one randomized controlled trial (37 hips, 55.6% female, mean age 34.2 years) were included. Anterior cortical perforation by suture anchors led to pain and impingement of pelvic neurovascular structures. The anterior acetabular positions (three to four o'clock) had the thinnest bone, smallest rim angles, and highest incidence of articular perforation. Drilling angles from 10° to 20° measured off the coronal plane were acceptable. The mid-anterior (MA) and distal anterolateral (DALA) portals were used successfully, with some studies reporting difficulty placing anchors at anterior locations via the DALA portal. Small-diameter (< 1 .8-mm) suture anchors had a lower in vivo incidence of articular perforation with similar stability and pull-out strength in biomechanical studies. Suture anchors at anterior acetabular rim positions (3–4 o'clock) should be inserted with caution. Large-diameter (>2.3-mm) suture anchors increase the likelihood of articular perforation without increasing labral stability. Inserting small-diameter (< 1 .8-mm) all-suture suture anchors (ASAs) from 10° to 20° using curved suture anchor drill guides, may increase safe insertion angles from all cutaneous portals. Direct arthroscopic visualization, use of fluoroscopy, distal-proximal insertion, and the use of nitinol wire can help prevent articular violation


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_3 | Pages 19 - 19
23 Feb 2023
Sandow M Cheng Z
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This paper presents an ongoing review of the use of a wedge-shaped porous metal augments in the shoulder to address glenoid retroversion as part of anatomical total shoulder arthroplasty (aTSA). Seventy-five shoulders in 66 patients (23 women and 43 men, aged 42 to 85 years) with Walch grade B2 or C glenoids underwent porous metal glenoid augment (PMGA) insertion as part of aTSA. Patients received either a 15º or 30º PMGA wedge (secured by screws to the native glenoid) to correct excessive glenoid retroversion before a standard glenoid component was implanted using bone cement. Neither patient-specific guides nor navigation were used. Patients were prospectively assessed using shoulder functional assessments (Oxford Shoulder Score [OSS], American Shoulder and Elbow Standardized Shoulder Assessment Form [ASES], visual analogue scale [VAS] pain scores and forward elevation [FE]) preoperatively, at three, six, and 12 months, and yearly thereafter, with similar radiological surveillance. Forty-nine consecutive series shoulders had a follow-up of greater than 24 months, with a median follow-up of 48 months (range: 24–87 months). Median outcome scores improved for OSS (21 to 44), ASES (24 to 92), VAS (7 to 0), and FE (90º to 140º). Four patients died, but no others were lost to follow-up. Apart from one infection at 18 months postoperatively and one minor peg perforation, there were no complications, hardware failures, implant displacements, significant lucency or posterior re-subluxations. Radiographs showed good incorporation of the wedge augment with correction of glenoid retroversion from median 22º (13º to 46º) to 4º. All but four glenoids were corrected to within the target range (less than 10º retroversion). The porous metal wedge-shaped augments effectively addressed posterior glenoid deficiency as part of aTSA for rotator cuff intact osteoarthritis, producing satisfactory clinical outcomes with no signs of impending future failure


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_16 | Pages 10 - 10
1 Oct 2014
Richter P Schicho A Gebhard F
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Minimally invasive placement of iliosacral screws (SI-screw) is becoming the standard surgical procedure for sacrum fractures. Computer navigation seems to increase screw accuracy and reduce intraoperative radiation compared to conventional radiographic placement. In 2012 an interdisciplinary hybrid operating theatre was installed at the University of Ulm. A floor-based robotic flat panel 3D c-arm (Artis zeego, Siemens, Germany) is linked to a navigation system (BrainLab Curve, BrainLab, Germany). With a single intraoperative 3D scan the whole pelvis can be visualised in CT-like quality. The aim of this study was to analyse the accuracy of SI-screws using this hybrid operating theater. 32 SI-screws (30 patients) were included in this study. Indications ranged from bone tumour resection with consecutive stabilisation to pelvic ring fractures. All screws were implanted using the hybrid operating theatre at the University of Ulm. We analysed the intraoperative 3D scan or postoperative computed tomography and classified the grade of perforation of the screws in the neural foramina and the grade of deviation of the screws to the cranial S1 endplate according to Smith et al. Grade 0 stands for no perforation and a deviation of less than 5 °. Grade 1 implies a perforation of less than 2 mm and a deviation of 5–10°, grade 2 a perforation of 2–4 mm and a deviation of 10–15° and grade 3 a perforation of more than 4 mm and a deviation of more than 15°. All patients were tested for intra- and postoperative neurologic complications and infections. The statistical analysis was executed using Microsoft Excel 2010. 32 SI-screws were implanted in the first 20 months after the hybrid operating theatre had been established in 2012. All 30 patients were included in this study (15 men, 15 women). The mean age was 59 years ±23 (13–95 years). 20 patients received a single screw in S1 (66.7%), 1 patient 2 unilateral screws in S1 and S2 (3.3%), one patient 2 bilateral screws in S1 (3.3%) and 8 patients a single screw stabilising both SI-joints (26.7%). 27 screws showed no perforation (84.4%), 1 screw a grade 1 perforation (3.1%) and 4 screws a grade 2 perforation (12.5%). There was no grade 3 perforation. Furthermore there was no perforation of the neural foramina or the ventral cortex in the axial plane of the SI-screws stabilising one SI-joint (24 screws). Only single SI-screws bridging both SI joints showed a perforation of the neural foramina (37% grade 0, 12.5% grade 1, 50% grade 2, 0% grade 3). In the frontal plane 23 screws (71.9%) showed a deviation of less than 5°. In 5 screws a grade 1 deviation (15.6%) and in 4 screws a grade 2 deviation (12.5%) could be found. There was no grade 3 deviation. There were no infections or neurological complications. The high image quality and large field of view in combination with an advanced navigation system is a great benefit for the surgeon. All SI-screws stabilising only one joint showed completely intraosseous placement. Single SI-screws bridging 2 SI-joints intentionally perforated the neural foramina ventrally in 5 cases because of dysmorphic sacral anatomy. This makes image-guided implantation of SI-screws in a hybrid operating theatre a very safe procedure


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_14 | Pages 86 - 86
1 Dec 2019
Trebse R Kanalec T Angelini K Baljak S Filipič T Levašic V
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Aim. ”There is not a lot of data of the frequency and impact of unwanted events including glove perforation, contamination of the surgical field (drape perforation, laceration, detachment, bone bounced back from an unsterile object), unsterile object in the surgical field (hair, sweat droplet…), defecation, elevated air temperature, and others. Mishaps occur in every surgical theatre. These events should influence the surgical site infection rate but it is not clear to what extent. We wanted to calculate the frequency and measure the impact of these events on the infection and revision rate of the relative patients.”. Method. ”In our institution, scrub nurses prospectively record untoward events in the theatres. Surgeons register complications before discharge. Stratified failures are recorded since 2002 within a registry. We analysed the respective databases and compared the revision and infection rate in the group with untoward effects with the outcome of all arthroplasty patients within the same time period. Two tailed Z statistical test was used for analysis.”. Results. “: Between 1.1.2012 and 31.12.2015 we operated 8130 prosthetic joints: 3994 THR and 3238 TKR including respectively 610 and 288 revisions. During this period we recorded 234 events (2.9 %) including 13 (0.16 %) defecations, 19 (0.2 %) contaminations with hair, 48 (0.6%) draping, gown or field sterility violations, 34 (0,4 %) glove perforations, 19 (0.5 %) occasions with elevated air temperature. In 37 (0,45%) surgeries there was a guest in the theatre. There were 8 (2.8%) infections and 10 (3.5%) revisions in the group with untoward events. The infection rate for all TJR was 0.64% the revision rate for any reason was 2.37%. For all the THR patient of the same study period was 2.1% for any reason and 0.7% for PJI and for the TKR 2.72 and 0.56 respectively. The difference is significant at p>0.05 for infection but not significant for revision for any reason.”. Conclusions. ”In our series, the potentially serious sterility disruptive events in the operative rooms did result in increased infection rate among the involved patients but not an increase in revision rate. There is no data about the rate and the impact of these events besides for perforated surgical gloves with higher reported incidences than in our study influencing infection rate if perioperative antibiotic prophylaxis was not used. Ours is thus the first study to report some numbers about these events.”


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_7 | Pages 125 - 125
1 Apr 2017
Kraay M
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The well-fixed cemented femoral stem and surrounding cement can be challenging to remove. Success requires evaluation of the quality of the cement mantle (interface lucency), position of the stem, extent of cement below the tip of the stem and skill with the specialised instruments and techniques needed to remove the stem and cement without perforating the femur. Smooth surfaced stems can usually be easily removed from the surrounding cement mantle with a variety of stem extractors that attach to the trunnion or an extraction hole on the implant. Roughened stems can be freed from the surrounding cement mantle with osteotomes or a narrow high speed burr and then extracted with the above instruments. Following this, the well-fixed cement mantle needs to be removed. Adequate exposure and visualization of the cement column is essential to remove the well-fixed cement without damage to the bone in the femur. This is important since fixation of a revision femoral component typically requires at least 4 cm of contact with supportive cortical bone, which can be difficult to obtain if the femur is perforated or if the isthmus damaged. Proximally, cement in the metaphyseal region can be thinned with a high speed burr, then split radially and removed piecemeal. It is essential to remember that both osteotomes and high speed burrs will cut thru bone easier than cement and use of these instruments poses a substantial risk of unintended bone removal and perforation of the femur if done improperly. These instruments should, as a result, be used under direct vision. Removal of more distal cement in the femur typically requires use of an extended femoral osteotomy (ETO) to allow for adequate access to the well-fixed cement in the bowed femoral canal. An ETO also facilitates more efficient removal of cement in the proximal femur. The ETO should be carefully planned so that it is distal enough to allow for access to the end of the cement column and still allow for stable fixation of a new implant. Too short of an ETO increases the risk of femoral perforation since the straight cement removal instruments cannot negotiate the bowed femoral canal to access the end of the cement column without risk of perforation. An ETO that is too distal makes cement removal easier, but may not allow for sufficient fixation of a new revision femoral stem. Cement below the level of the ETO cannot be directly visualised and specialised instruments are necessary to safely remove this distal cement. Radiofrequency cement removal devices use high frequency (ultrasonic) radio waves to melt the cement within the canal. Although cement removal with these devices is time consuming and tedious, they do substantially reduce the chances of femoral perforation. These devices can, however, generate considerable heat locally and can result in thermal injury to the bone and surrounding tissues. Once the distal end of the cement mantle is penetrated, backbiting or hooked curettes can be use to remove any remaining cement from within the canal. It is important that all cement be removed from the femur since reamers used for preparation of the distal canal will be deflected by any retained cement, which could result in eccentric reaming and inadvertent perforation of the femur and make fixation of a new implant very challenging. An intra-operative x-ray can be very helpful to insure that all cement has been removed before reaming is initiated. One should always plan for a possible femoral perforation and have cortical strut grafts and a stem available that will safely bypass the end of the cement column and the previous cement restrictor


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_28 | Pages 97 - 97
1 Aug 2013
Richter P Rahmanzadeh T Gebhard F Krischak G Arand M Weckbach S Kraus M
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INTRODUCTION. Isolated injuries of the sacral bone are rare. The pathomechanism of these injuries are usually high velocity accidents or falls from large heights. The computer-assisted implantation of iliosacral screws (SI-screw) becomes more important in the treatment of dorsal pelvic ring fractures. The advantage of the minimal-invasive screw placement is the reduction of the non-union and deep wound infection rate. Another advantage of computer-navigated SI-screw placement is the reduction of intraoperative radiation for the patient and the surgical staff. The purpose of this study was to analyse the position of navigated iliosacral screws. METHODS. In the study group 74 screws (49 patients) were included and radiologically analysed. All screws were implanted using 3D-navigation (BrainLAB Vector Vision, Brainlab, Germany). Navigation was always executed with the same 3D c-arm (ARCADIS Orbic 3D, Siemens, Germany) and navigation system. We determined the grade of perforation and angular deviation in the postoperative CT-scans in all screws. The classification was performed according to Smith et al in 4 grades. Grade 0 implies no perforation and grade 1 a perforation less than 2 mm. Grade 2 correlates a perforation of 2–4 mm and grade 3 a perforation of more than 4 mm. Furthermore the intra- and postoperative complications as well as the body-mass-index, the co-morbidities and the duration of radiation were documented. The statistical analysis was executed using Microsoft Excel 2003. RESULTS. The mean age of the 49 patients was 42.2 years ± 18 (16–79 years). 28 male and 21 female patients were included. 25 patients received a single iliosacral screw in S1. In 19 cases a screw in S1 and S2 was placed on the same side. Four patients got bilateral SI-screws in S1 and another patient received bilateral screw placement in S1 as well as an additional screw in S2. The mean operation time was 100 min ±103 (20–540 min). The isolated time for SI-placement was 50 min ± 20 (20–93 min). The mean radiation time was 3 min ± 1.7 (0.9–7.4 min) (n = 28). Altogether 84% of the screws showed an intraosseous position (grade 0). In the axial plane 7 screws perforated ventrally, 5 screws penetrated the adjacent neural foramen. In the frontal plane the screws showed greater variations, 61% deviated less than 5° (grade 0). In the study group 5 screws needed surgical revision because of either malplacement or postoperative pain. There were no infections or neurological complications. There was no statistical correlation between screw perforation and the body-mass-index. CONCLUSION. The computer-assisted implantation of iliosacral screws is a safe method in relation to screw perforation. It shows a high security and accuracy concerning the ventral and dorsal cortical perforation. There is a frequent angular deviation in the frontal view without appearance of screw perforation or mechanic, neurologic and angiologic complications. The minimal-invasive procedure shows a low postoperative revision rate


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_10 | Pages 12 - 12
1 May 2016
Lombardo D Prey B Khan J Sabesan V
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Background. A challenge to obtaining proper glenoid placement in total shoulder arthroplasty is eccentric posterior bone loss and associated glenoid retroversion. This bone loss can lead to poor stability and perforation of the glenoid during arthroplasty. The purpose of this study was to evaluate the three dimensional morphology of the glenoid with associated bone loss for a spectrum of osteoarthritis patients using 3-D computed tomography imaging and simulation software. Methods. This study included 29 patients with advanced glenohumeral osteoarthritis treated with shoulder arthroplasty. Three-dimensional (3D) reconstruction of preoperative CT images was performed using image analysis software. Glenoid bone loss was measured at ten, vertically equidistant axial planes along the glenoid surface at four distinct anterior-posterior points on each plane for a total of 40 measurements per glenoid. The glenoid images were also fitted with a modeled pegged glenoid implant to predict glenoid perforation. Results. The average bone loss was greatest posteriorly in the AP plane at the central axis of the glenoid in the SI plane. Walch A2 and B1 shoulders had bone loss more centrally located, while Walch B2 shoulders displayed more posterior and inferior bone loss. There was a significant difference in the overall average bone loss for patients with no predicted peg perforation compared to patients predicted to have peg perforation (p=0.37). Peg perforation was most common in Walch B2 shoulders, in the posterior direction, and involved the central and posterior-inferior peg. Discussion. These data demonstrate a clear, anatomical pattern of glenoid bone loss for different classes of glenohumeral arthritis. These findings can be used to develop various models of glenoid bone loss to guide surgeons, predict failures, and help develop better glenoid implant


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_3 | Pages 135 - 135
1 Feb 2017
Geller J Herschmiller T Cunn G Murtaugh T Gardner T
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Traditional medial soft tissue release for balancing of the varus knee in total knee arthroplasty can lead to an inconsistent reduction in medial tension. The purpose of this study is to establish whether sequential needle puncturing of the medial collateral ligament (MCL) can be a safe and predictable method for medial release. Total knee prostheses were implanted in 14 cadaveric specimens by a single surgeon. Medial tension was measured in flexion and extension by a pressure sensor with implants in place, and calipers after removal of implants and gap distraction under constant tension. Measurements were performed after each of 5 sets of 5 punctures of the MCL with an 18-gauge needle and following 5 transverse perforations with an 11-blade. A consistent valgus force was applied after each set of MCL punctures with a pneumatic cylinder. Pearson's correlation was used to compare pressure sensor measurement with gap distance measurement under tension. The pressure as detected by the sensor after each set of 5 punctures was analyzed by a repeated measures two-way ANOVA and a Tukey multiple comparisons test to determine a significant decreases between puncture sets. The pressure sensor device correlated more closely with systematic tissue release (r=0.59 for % change from baseline) than did measurements of gap increase under tension (r= −0.22). All knees had ≤5mm of medial opening with up to 25 needle punctures. Two knees had <5mm of medial opening in flexion after blade perforation. The mean pressure decreases in 90 degrees flexion, mid-flexion and extension were 11.2, 9.4 and 9.9 lbs respectively after 5 needle punctures and 8.1, 11.5 and 9.6 lbs between 5 and 15. Significant pressure decreases were seen after 5 and 10 needle punctures and again after blade perforation (p<0.05). Needle puncture of the deep and superficial MCL leads to a significant and reliable decrease in medial tension over the first 15, with diminishing effect up to 25 punctures. This method may be employed when up to 20 lbs reduction in medial pressure is desired. Blade perforation after needle puncture should be approached with caution


Orthopaedic Proceedings
Vol. 97-B, Issue SUPP_1 | Pages 52 - 52
1 Feb 2015
Kraay M
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The well-fixed cemented femoral stem and surrounding cement can be challenging to remove. Success requires evaluation of the quality of the cement mantle (interface lucency), position of the stem, extent of cement below the tip of the stem and skill with the specialised instruments and techniques needed to remove the stem and cement without perforating the femur. Smooth surfaced stems can usually be easily removed from the surrounding cement mantle with a variety of stem extractors that attach to the trunnion or an extraction hole on the implant. Roughened stems can be freed from the surrounding cement mantle with osteotomes or a narrow high speed burr and then extracted with the above instruments. Following this, the well fixed cement mantle needs to be removed. Adequate exposure and visualization of the cement column is essential to remove the well-fixed cement without damage to the bone in the femur. This is important since fixation of a revision femoral component typically requires at least 4cm of contact with supportive cortical bone, which can be difficult to obtain if the femur is perforated or if the isthmus damaged. Proximally, cement in the metaphyseal region can be thinned with a high speed burr, then split radially and removed piecemeal. It is essential to remember that both osteotomes and high speed burrs will cut thru bone easier than cement and use of these instruments poses a substantial risk of unintended bone removal and perforation of the femur if done improperly. These instruments should, as a result, be used under direct vision. Removal of more distal cement in the femur typically requires use of an extended femoral osteotomy (ETO) to allow for adequate access to the well-fixed cement in the bowed femoral canal. An ETO also facilitates more efficient removal of cement in the proximal femur. The ETO should be carefully planned so that it is distal enough to allow for access to the end of the cement column and still allow for stable fixation of a new implant. Too short of an ETO increases the risk of femoral perforation since the straight cement removal instruments cannot negotiate the bowed femoral canal to access the end of the cement column without risk of perforation. An ETO that is too distal makes cement removal easier, but may not allow for sufficient fixation of a new revision femoral stem. Cement below the level of the ETO cannot be directly visualised and specialised instruments are necessary to safely remove this distal cement. Radiofrequency cement removal devices (OSCAR) use high frequency (ultrasonic) radio waves to melt the cement within the canal. Although cement removal with these devices is time consuming and tedious, they do substantially reduce the chances of femoral perforation. These devices can, however, generate considerable heat locally and can result in thermal injury to the bone and surrounding tissues. Once the distal end of the cement mantle is penetrated, backbiting or hooked curettes can be used to remove any remaining cement from within the canal. It is important that all cement be removed from the femur since reamers used for preparation of the distal canal will be deflected by any retained cement, which could result in eccentric reaming and inadvertent perforation of the femur and make fixation of a new implant very challenging. An intraoperative x-ray can be very helpful to insure that all cement has been removed before reaming is initiated


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_12 | Pages 16 - 16
1 Jul 2014
Galatz L
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Peri-prosthetic fractures around implants in the proximal humerus can present substantial challenges. Most individuals who undergo upper limb arthroplasty tend to be osteopenic to begin with, and the anatomy of the proximal humerus does not provide an excess of bone to work with. Therefore, peri-prosthetic fractures pose difficulties to rotator cuff function and implant stability. There are multiple classification systems, but series are small and the classification does not always lead to treatment algorithms. Risk factors for humeral fractures after shoulder arthroplasty include endosteal notching, cortical perforation, varus malalignment, stem perforation, ipsilateral shoulder and elbow arthroplasties, and loose stems. Many of these risk factors are directly related to technical errors at the time of surgery. Poor exposure can lead to aberrant starting point and errors in reaming. Oversized prostheses can lead to cortical perforation or even stem perforation. Proper positioning of the patient on the table and surgical releases help avoid these technical errors. Peri-prosthetic fractures should be carefully evaluated radiographically for stability. Two important considerations: 1. Is the implant stable? 2. Is the fracture stable? Generally, if the implant is unstable, the implant must be revised. In the setting of a stable implant, many humeral fractures can be treated nonoperatively. Many fractures at or below the level of the tip of the implant can be treated as typical humeral fractures. Options for fixation include plates with cables or long stem prostheses which bypass the fracture. Displaced tuberosity fractures are treated with suture or wire fixation. Risk factors for a poor outcome include increased time to union, skin breakdown, and stiff shoulder


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_10 | Pages 51 - 51
1 Jun 2018
Kraay M
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The well-fixed femoral stem can be challenging to remove. Removal of an extensively osteointegrated cementless stem requires disruption of the entire implant-bone interface while a well-fixed cemented stem requires complete removal of all adherent cement from the underlying cortical bone in both the metaphysis and diaphysis of the femur. In these situations, access to those areas of the femur distal to the metaphyseal flare that are beyond the reach of osteotomes and high speed burrs is necessary. This typically requires use of an extended femoral osteotomy (ETO). The ETO should be carefully planned so that it extends distal enough to allow for access to the end of the stem or cement column and still allow for stable fixation of a new implant. Too short of an ETO increases the risk of femoral perforation by straight burrs, trephines or cement removal instruments that cannot negotiate the bowed femoral canal to access the end of the cement column or end of the stem without risk of perforation. The ETO should also be long enough to allow for fixation with at least 2 cerclage cables. An ETO that is too distal makes implant and cement removal easier, but may not allow for sufficient fixation of a new revision femoral stem. After insertion of the revision stem, the osteotomy is reduced back around the stem and secured in place with cerclage cables


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_10 | Pages 123 - 123
1 May 2016
Walsh W Bertollo N Schaffner D Christou C Oliver R Hale D
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Introduction. Bone marrow stimulation has been a successful treatment option in cartilage repair and microfracture was the procedure of choice since the late 1980s. Despite its success in young and active patients, microfracture has inherent shortcomings such as shallow channels, wall compression, and non-standardized depth and diameter. This in vitro study assessed bone marrow access comparing microfracture, 1 and 2mm K-Wires, 1mm drill, and a recently introduced standardized subchondral bone needling procedure (Nanofracture) that creates 9mm deep and 1mm wide channels. Methods. An adult ovine model was used to assess access to bone the marrow spaces as well as effects on bone following microfracture, nanofracture, K-wire, and drilling following ethical clearance. All bone marrow stimulation techniques were conducted on a full thickness articular cartilage defect on the medial femoral condyles by the same surgeon. The same groups were repeated in vitro in 4 paired ovine distal femurs. MicroCT (Inveon Scanner, Siemens, Germany) was performed using 3D reconstruction and 25 micron slice analysis (MIMICS, Materialise, Belgium). Results. Microfracture elicited shallow depth with bone compression surrounding the channels. Trabecular channel access was limited; the channel depth and diameter were non-standardized and highly user and instrument dependent. Nanofracture demonstrated deep cancellous bone perforation with a high number of open trabecular channels. K-Wire drilling with both diameters resulted in well-defined channel walls, outlined by fine osseous deposits. Trabecular channel access was limited. The diameter of bone perforation is standardized, but depth is defined by visual controls. 1mm drill bit reaming demonstrated better osseous evacuation, but still limited trabecular marrow access. Discussion and Conclusion. Nanofracture resulted in thin, fragmented cancellous bone channels without rotational heat generation. Compared to microfracture, drilling and K-Wire stimulation, nanofracture showed superior bone marrow access with multiple trabecular access channels extending 9mm into subchondral bone


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_4 | Pages 130 - 130
1 Feb 2017
Ma S Goh E Patel B Jin A Boughton O Cobb J Hansen U Abel R
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Introduction. Bisphosphonates (BP) are the first-line therapy for preventing osteoporotic fragility fractures. However, concern regarding their efficacy is growing because bisphosphonate use is associated with over-suppression of remodeling. Animal studies have reported that BP therapy is associated with accumulation of micro-cracks (Fig. 1) and a reduction in bone mechanical properties, but the effect on humans has not been investigated. Therefore, our aim was to quantify the mechanical strength of bone treated with BP, and correlate this with the microarchitecture and density of micro-damage in comparison with untreated osteoporotic hip-fractured and non-fractured elderly controls. Methods. Trabecular bone cores from patients treated with BP were compared with patients who had not received any treatment for bone osteoporotic disease. Non-fractured cadaveric femora from individuals with no history of bone metabolic disease were also used as controls. Cores were imaged in high resolution (∼1.3µm) using Synchrotron X-ray tomography (Diamond Light Source Ltd.) The scans were used for structural and material analysis, then the cores were mechanically tested in compression. A novel classification system was devised to characterise features of micro-damage in the Synchrotron images: micro-cracks, diffuse damage and perforations. Synchrotron micro-CT stacks were visualised and analysed using ImageJ, Avizo and VGStudio MAX. Results. Our findings demonstrated that patients treated with BP (17.2 MPa) had significantly lower tissue strength than untreated fracture (24.0 MPa) and non-fracture controls (28.0 MPa). Yet treated and untreated hip-fracture patient's exhibited comparable bone microarchitecture, volume fraction, apparent and material density. The data also revealed that the BP group had the highest micro-damage density across all groups. The BP group (7.7/mm. 3. ) also exhibited significantly greater micro-crack density than the fracture (4.3/mm. 3. ) and non-fracture (4.1/mm. 3. ) controls. Furthermore, the BP group (1.9/mm. 3. ) demonstrated increased diffuse damage when compared to the fracture (0.3/mm. 3. ) and non-fracture (0.8/mm. 3. ) controls. In contrast, the BP group (1.9. mm. 3. ) had fewer perforations than fracture (3.0/mm. 3. ) and non-fracture controls (3.9/mm. 3. ). Discussion. Despite having comparable microarchitecture apparent and material density, patients taking BP exhibited weaker tissue strength compared to the controls. This weakness is likely to be the the result of the increased accumulation of micro-damage found in BP treated bone. BP inhibits bone remodelling, thereby reducing the number of perforated trabeculae, meanwhile over-suppression leads to the accumulation of micro-cracks and diffuse damage which reduce strength. Conclusion. In our subgroup of hip-fracture patients, BP therapy appeared to offer no mechanical advantage in resisting femoral fractures. BP accumulated micro-damage may have weakened the trabecular bone in the femoral head and neck thereby, therefore increasing the risk of a fracture during a trip or fall