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Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_20 | Pages 77 - 77
1 Dec 2017
Mak MC Chui EC Tse W Ho P
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Scaphoid non-union results the typical humpback deformity, pronation of the distal fragment, and a bone defect in the non-union site with shortening. Bone grafting, whether open or arthroscopic, relies on fluoroscopic and direct visual assessment of reduction. However, because of the bone defect and irregular geometry, it is difficult to determine the precise width of the bone gap and restore the original bone length, and to correct interfragmentary rotation. Correction of alignment can be performed by computer-assisted planning and intraoperative guidance. The use of computer navigation in guiding reduction in scaphoid non-unions and displaced fractures has not been reported. Objective. We propose a method of anatomical reconstruction in scaphoid non-union by computer-assisted preoperative planning combined with intraoperative computer navigation. This could be done in conjunction with a minimally invasive, arthroscopic bone grafting technique. Methods. A model consisting of a scaphoid bone with a simulated fracture, a forearm model, and an attached patient tracker was used. 2 titanium K-wires were inserted into the distal scaphoid fragment. 3D images were acquired and matched to those from a computed tomography (CT) scan. In an image processing software, the non-union was reduced and pin tracts were planned into the proximal fragment. The K-wires were driven into the proximal fragment under computer navigation. Reduction was assessed by direct measurement. These steps were repeated in a cadaveric upper limb. A scaphoid fracture was created and a patient tracker was inserted into the radial shaft. A post-fixation CT was obtained to assess reduction. Results and Discussion. In both models, satisfactory alignment was obtained. There were minimal displacement and articular stepping, and scaphoid length was restored with less than 1mm discrepancy. This study demonstrated that an accurate reduction of the scaphoid in non-unions and displaced fractures can be accurately performed using computed navigation and computer-assisted planning. It is the first report on the use of computer navigation in correction of alignment in the wrist


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_3 | Pages 13 - 13
1 Mar 2021
Chambers S Padmore C Fan S Grewal R Johnson J Suh N
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To determine the biomechanical effect of increasing scaphoid malunion and scaphoid non-union on carpal kinematics during dynamic wrist motion using an active wrist motion simulator. Seven cadaveric upper extremities underwent active wrist flexion and extension in a custom motion wrist simulator with scaphoid kinematics being captured with respect to the distal radius. A three-stage protocol of progressive simulated malunion severity was performed (intact, 10° malunion, 20° malunion) with data analyzed from 45° wrist flexion to 45° wrist extension. Scaphoid malunions were modelled by creating successive volar wedge osteotomies and fixating the resultant scaphoid fragments with 0.062 Kirshner wires. At the completion of malunion motion trials, a scaphoid non-union trial was carried out by removing surgical fixation to observe motion differences from the malunion trials. Motion of the scaphoid, lunate, capitate, and trapezium-trapezoid was recorded and analyzed using active optical trackers. Increasing scaphoid malunion severity did not significantly affect scaphoid or trapezium-trapezoid motion (p>0.05); however, it did significantly alter lunate motion (p<0.001). Increasing malunion severity resulted in progressive lunate extension across wrist motion (Intact – Mal 10: mean dif. = 7.1° ± 1.6, p<0.05; Intact – Mal 20: mean dif. = 10.2° ± 2.0, p<0.05;) although this change was not as great as the difference seen during non-union trials (native – non-union: mean dif. = 13.8° ± 3.7, p<0.05). In this in-vitro model, increasing scaphoid malunion severity was associated with progressive extension of the lunate in all wrist positions. The clinical significance of this motion change is yet to be elucidated, but this model serves as a basis for understanding the kinematic consequences of scaphoid malunion deformities


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_1 | Pages 28 - 28
1 Jan 2022
Sree DV Iyengar KP Loh D Shrestha S Loh WYC
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Abstract. Background. Scaphoid non-union can result in pain, altered wrist kinematics leading to a Scaphoid Non-union Advance Collapse, ultimately to symptomatic radio-carpal arthritis. Open techniques have their limitations. We describe the rationale, surgical technique and outcomes of our series of arthroscopic bone-grafting (ABG) and fixation of scaphoid non-union. Methods. We performed a prospective single-surgeon series of 22 consecutive patients with clinico-radiologically established scaphoid non-union between March 2015 and April 2019. Data was collected from Electronic Patient Records, Patient Archived Computer system (PACS) and hand therapy assessments. We collected demographic data including age, hand-dominance, occupation and mechanism of injury. The Disabilities of the Arm, Shoulder and Hand Score (Quick DASH), Mayo wrist score, Patient Rated Wrist Evaluation (PRWE) and grip-strength measurements were collected preoperatively and at follow-up appointments. Results. There was an improvement in all outcome measures when comparing preoperative and postoperative results. The Quick DASH score improved by a mean of 24 points, Mayo wrist and PRWE scores improved by 15.1 and 29.7 points, respectively. Grip-strength analysis also improved by 6.1 kgf (Right) and 3.3kgf (Left). Follow-up computerised tomography scans revealed union in 18/22 patients with 2 patients lost to follow-up. One patient required revision ABG procedure to achieve union. Conclusion. Arthroscopic bone grafting and fixation of scaphoid non-union allows a minimally invasive method of managing these injuries. It has advantages of minimal morbidity and accurate articular reduction resulting in less postoperative stiffness and increased functional outcomes. It is an effective alternative to conventional open treatment of established scaphoid non-union


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_6 | Pages 37 - 37
1 Jul 2020
Lalone E Grewal R Seltser A Albakri K MacDermid J Suh N Perrin M
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Scaphoid fractures are a common injury accounting for more than 58% of all carpal bone fractures(1,2). Biomechanical studies have suggested that scaphoid mal-union may lead to altered carpal contact mechanics causing decreased motion, pain and arthritis(1,2). The severity of mal-union required to cause deleterious effects has yet to be established. This limits the ability to define surgical indications or impacts on prevention of posttraumatic arthritis. Computed tomography has been shown to be a useful in determining the 3D implications of altered bony alignment on the joint contact mechanics of surrounding joints. The objective of this study was to report mid-term follow-up image-based outcomes of patients with scaphoid mal-unions to determine the extent to which arthritic changes and decreased joint space is present after a minimum of 4 years following fracture. Participants (n=14) who had previously presented with a mal-united scaphoid fracture (indicated by a Height:Length Ratio >0.6) between November 2005 and November 2013 were identified and contacted. A short-arm thumb spica case was used to treat X patients and X required surgical management. Baseline and follow-up CT images, were performed with the wrist in radial deviation and positioned such that the long axis of the scaphoid was perpendicular to the axis of the scanner. Three-dimensional inter-bone distance (joint space), a measure of joint congruency and 3D alignment, was quantified from reconstructed CT bone models of the distal radius, scaphoid, lunate, capitate, trapezium and trapezoid from both the baseline and follow-up scans(3). Repeated measures ANOVA was used to detect differences in contact area (mm2) between baseline and follow-up CT's for the radioscaphoid, scaphocapitate and scaphotrapezium-trapezoid joint. The average age of participants was 43.1 years (16–64 years old). There was significant loss of joint space, indicated by a greater joint contact area 3–4 years post fracture, between baseline and follow-up reconstruction models, at the scaphocapitate (mean difference: 21.5±146mm2, p=0.007) and scaphotrapezoid joints (mean difference: 18.4 ±28.6mm2, 0.042). Significant differences in the measured contact area was not found for the radioscaphoid (0.153) and scaphotrapezium joints (0.72). Additionally, the scaphoid, qualitatively, appears to track in the vorsal direction in the majority of patients following fracture. Increased joint contact area in the scaphocapitate and scaphotrapezoid joint 3–4 years following fracture results from decreased 3D joint space and overall narrowing. Joint space narrowing, while not significantly different for all joints examined, was reduced for all joints surrounding the scaphoid. Decreased joint space and increased contact area detectable within this short interval might be suggestive of a trajectory for developing arthritis in the longer term, and illustrates the potential value of these measures for early detection. Longer term follow-up and correlation to clinical outcomes are needed to determine the importance of early joint space narrowing, and to identify those most at risk


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_13 | Pages 11 - 11
1 Nov 2019
Mittal S Kumar A Trikha V
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Introduction. Surgeons fixing scaphoid fractures need to be familiar with its morphological variations and their implications on safe screw placement during fixation of these fractures. Literature has limited data in this regard. The purpose of this CT-based study was to investigate scaphoid morphometry and to analyse the safe trajectories of screw placement in scaphoid. Methods. We measured the coronal and Sagittal widths of scaphoid in CT-scans of 60 patients using CT based data from 50 live subjects with intact scaphoid. Safe placements for screws with diameters of 1.7mm, 2.4mm, 3.5mm and 4mm were studied using trajectories with additional 2mm safety corridor. Results. The mean width of proximal segment in coronal and sagittal plane were 6.39mm (4.5–8.7) and 11.44mm (8.4–14.1) respectively. For the waist region, the mean coronal, sagittal width were 8.03mm (6.3–10.2mm) and 9.02mm (7–11.4mm) respectively. For distal segment, the mean coronal and sagittal width were 10.58mm (8.2–14.6mm) and the 9.59mm (7.3–11.9mm) respectively. The coronal and sagittal widths were significantly different from each other in all three zones. All scaphoid were capable of safely containing single 4mm screw and two parallel 1.7mm screws. Conclusion. Our study shows that there is considerable variation in scaphoid morphometry. Among the parameters, the waist region measurements show the least variation. The screw lengths do not always correlate to the overall longitudinal extent of scaphoid and can be planned preoperatively using CT-scans. Surgeons treating these fractures should opt for a CT-based analysis regarding the screw direction and length and need to be familiar with the variations in scaphoid morphometry


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVIII | Pages 52 - 52
1 Sep 2012
Al-Sanawi H Gammon B Sellens RW John PS Smith EJ Ellis RE Pichora DR
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Purpose. Primary internal fixation of uncomplicated scaphoid fractures offers many advantages compared to conventional casting. However, ideal fixation placement along the central scaphoid axis can be challenging, especially if the procedure is performed percutaneously. Because of the lack of direct visualization, percutaneous procedures demand liberal use of imaging, thereby increasing exposure to harmful radiation. It has been demonstrated that computer-assisted navigation can improve the accuracy of guidewire placement and reduce X-ray exposure in procedures such as hip fracture fixation. Adapting the conventional computer-assist paradigm, with preoperative imaging and intraoperative registration, to scaphoid fixation is not straightforward, and thus a novel tactic must be conceived. Method. Our navigation procedure made use of a flatpanel C-arm (Innova, GE Healthcare) to obtain a 3D cone-beam CT (CBCT) scan of the wrist from which volumetrically-rendered images were created. The relationship between the Innova imager and an optical tracking system (OptoTrak Certus, Northern Digital Inc.) was calibrated preoperatively so that an intraoperatively-acquired image could be used for real-time navigation. Optical markers fitted to a drill guide were used to track its orientation, which was displayed on a computer monitor relative to the wrist images for navigation. Randomized trials were conducted comparing our 3D navigated technique to two alternatives: one using a standard portable C-arm, and the other using the Innova flatpanel C-arm with 2D views and image intensification. A model forearm with an exchangeable scaphoid was constructed to provide consistency between the trials. The surgical objective was to insert a K-wire along the central axis of a model scaphoid. An exposure meter placed adjacent to the wrist model was used to record X-ray exposure. Procedure time and drill passes were also noted. CT scans of the drilled scaphoids were used to determine the shortest distance from the drill path to the scaphoid surface. Results. The closest distance from the drill path to the scaphoid surface was significantly larger using navigation compared to the 2D Innova method (p<0.05). Fewer drill passes were required using navigation compared to a conventional C-arm (p<0.01). Navigated procedures were significantly longer, although the overall time remained clinically acceptable (∼4min). There was no significant difference in radiation exposure to the patient between the three methods. The 3D CBCT image was acquired remotely in the navigated approach, so conceivably the exposure to the surgeon was much less than the other techniques. Conclusion. Computer-assisted navigation was successfully adapted to percutaneous scaphoid fixation without requiring the tedious preoperative imaging and intraoperative registration that typically plague these procedures. Navigation resulted in superior central screw placement with fewer drilling attempts in comparison to conventional techniques


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_28 | Pages 85 - 85
1 Aug 2013
Khamaisy S Peleg E Segal G Hamad A Luria S
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Purpose. The surgical treatment of scaphoid fractures consists of reduction of the fracture followed by stable internal fixation using a headless compression screw. Proper positioning of the screw remains technically challenging and therefore computer assisted surgery may have an advantage. Navigation assisted surgery requires placement and registration of stable reference markers which is technically impossible in a small bone like the scaphoid. Custom made wrist-positioning devices with built-in reference markers have been developed for this purpose. The purpose of this study was to evaluate a different method of navigation assisted scaphoid fracture fixation. Temporary stabilisation with a pin of the scaphoid to the radius enables placement of the reference markers on the radius. Our hypothesis was that this method will achieve precise fracture fixation, superior to the standard free hand technique. Methods. In 20 identical saw bone models with mobile scaphoids, the scaphoid was stabilised to the radius using one Kirschner wire (KW). An additional KW representing the fixating screw was placed either using the Mazor Renaissance Robotic System (MAZOR Surgical Technologies, Israel) or standard free hand technique. CT scans were performed prior to fixation and after fixation in order to plan the location of the KW and compare this planned location with the final result. Results. No significant difference was found between the measures of KW location between groups and in comparison with the planned location, including entry and exit points of the KW, length of KW through the scaphoid (mean axis length of 28.7 mm [SD 1.5] with the robot system versus 29.6 mm [SD 2.1] with the free hand technique) and difference in angle of fixation with the planned axis of fixation (mean of 1.7 degrees [SD 5.5] with the robot versus 3.8 degrees [SD 5.6] free hand). Significant differences were found between exposure to radiation (mean of 0.07 Rad [SD 0.04] with the robot system versus 13.9 Rad [SD 18.4] with the free hand technique; p=0.04) and the number of attempts in placing the KW (mean of 1.1 attempts [SD 0.32] with the robot versus 8 attempts [SD 6.65] free hand; p=0.01). Conclusion. Computer assisted fixation of a scaphoid fracture was found to be as accurate as the free hand technique, after fixation of the scaphoid to the radius, without the need for a custom splint. It was also shown to be superior by decreasing the exposure to radiation and number of attempts of KW placement


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_8 | Pages 37 - 37
1 Aug 2020
Milad D Smit K Carsen S Cheung K Karir A
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True scaphoid fractures of the wrist are difficult to diagnose in children. In 5–40% of cases, a scaphoid fracture may not be detectable on initial X-ray, some fractures may take up to six weeks to become evident. Since missing a scaphoid fracture may have serious implications, many children with a suspected or “clinical” scaphoid fracture, but normal radiographs, may be over-treated. The purpose of this study was to identify predictors of true scaphoid fractures in children. A retrospective cohort study was performed using electronic medical records for all patients over a two-year period presenting to a tertiary paediatric hospital with hand or wrist injury. Charts were identified by ICD-10 diagnostic codes and reviewed for pre-specified inclusion and exclusion criteria. Patients with either a clinical or true scaphoid fracture were included. When a scaphoid fracture was suspected, but imaging was negative for fracture, the diagnosis of a clinical scaphoid fracture was made. True scaphoid fractures were diagnosed when a fracture was evident on any modality of medical imaging (X-ray, CT, MRI) at any time post-injury. Over the two-year study period, 148 patients (60 scaphoid fractures, 88 non-fractures) met inclusion and exclusion criteria for review. Mean (±SD) age was 13±2 years and 52% were male. The left wrist was injured in 61% of cases. Of the 60 true scaphoid fractures, mean age was 14±2 years, and 69% were male. Fracture location was primarily at the waist (48%) or distal pole (45%) of the scaphoid. Sports were the prevailing mechanism of injury. Six (11%) underwent surgery. Multivariate logistic regression demonstrated that older age, male gender, and right-sided injury were predictors of scaphoid fracture with odds ratios of 1.3 (95% CI: 1.1–1.6, p=0.005), 2.8 (95% CI: 1.3–6, p=0.007), and 2.4 (95% CI: 1.1–5.2, p=0.025). Older age, male gender, and right-sided injury may be predictors of scaphoid fractures in children. Further evidence to support this may enable the formulation of clinical guidelines or rules to reduce the overtreatment of children presenting with a clinical scaphoid fracture


The Journal of Bone & Joint Surgery British Volume
Vol. 94-B, Issue 2 | Pages 276 - 280
1 Feb 2012
Buijze GA Weening AA Poolman RW Bhandari M Ring D

Using inaccurate quotations can propagate misleading information, which might affect the management of patients. The aim of this study was to determine the predictors of quotation inaccuracy in the peer-reviewed orthopaedic literature related to the scaphoid. We randomly selected 100 papers from ten orthopaedic journals. All references were retrieved in full text when available or otherwise excluded. Two observers independently rated all quotations from the selected papers by comparing the claims made by the authors with the data and expressed opinions of the reference source. A statistical analysis determined which article-related factors were predictors of quotation inaccuracy. The mean total inaccuracy rate of the 3840 verified quotes was 7.6%. There was no correlation between the rate of inaccuracy and the impact factor of the journal. Multivariable analysis identified the journal and the type of study (clinical, biomechanical, methodological, case report or review) as important predictors of the total quotation inaccuracy rate. We concluded that inaccurate quotations in the peer-reviewed orthopaedic literature related to the scaphoid were common and slightly more so for certain journals and certain study types. Authors, reviewers and editorial staff play an important role in reducing this inaccuracy


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_7 | Pages 94 - 94
1 Jul 2020
Undurraga S Au K Salimian A Gammon B
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Longstanding un-united scaphoid fractures or scapholunate insufficiency can progress to degenerative wrist osteoarthritis (termed scaphoid non-union advanced collapse (SNAC) or scapho-lunate advanced collapse (SLAC) respectively). Scaphoid excision and partial wrist fusion is a well-established procedure for the surgical treatment of this condition. In this study we present a novel technique and mid-term results, where fusion is reserved for the luno-capitate and triquetro-hamate joints, commonly referred to as bicolumnar fusion. The purpose of this study was to report functional and radiological outcomes in a series of patients who underwent this surgical technique. This was a prospective study of 23 consecutive patients (25 wrists) who underwent a bicolumnar carpal fusion from January 2014 to January 2017 due to a stage 2 or 3 SNAC/SLAC wrist, with a minimum follow-up of one year. In all cases two retrograde cannulated headless compression screws were used for inter-carpal fixation. The clinical assessment consisted of range of motion, grip and pinch strength that were compared with the unaffected contralateral side where possible. Patient-reported outcome measures, including the DASH and PRWE scores were analysed. The radiographic assessment parameters consisted of fusion state and the appearance of the radio-lunate joint space. We also examined the relationship between the capito-lunate fusion angle and wrist range of motion, comparing wrists fused with a capito-lunate angle greater than 20° of extension with wrists fused in a neutral position. The average follow-up was 2.9 years. The mean wrist extension was 41°, flexion 36° and radial-ulnar deviation arc was 43° (70%, 52% and 63% of contralateral side respectively). Grip strength was 40 kg and pinch strength was 8.9 kg, both 93% of contralateral side. Residual pain for activities of daily living was 1.4 (VAS). The mean DASH and PRWE scores were 19±16 and 29±18 respectively. There were three cases of non-union (fusion rate of 88%). Two wrists were converted to total wrist arthroplasty and one partial fusion was revised and healed successfully. Patients with an extended capito-lunate fusion angle trended toward more wrist extension but this did not reach statistical significance (P= 0.07). Wrist flexion did not differ between groups. Radio-lunate joint space narrowing progressed in 2 patients but did not affect their functional outcome. After bicolumnar carpal fusion using retrograde headless screws, patients in this series maintained a functional flexion-extension arc of motion, with grip-pinch strength that was close to normal. These functional outcomes and fusion rates were comparable with standard 4-corner fusion technique. A capito-lunate fusion angle greater than 20° may provide more wrist extension but further investigation is required to establish this effect. This technique has the advantage that compression screws are placed in a retrograde fashion, which does not violate the proximal articular surface of the lunate, preserving the residual load-bearing articulation. Moreover, the hardware is completely contained, with no revision surgery for hardware removal required in this series


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_13 | Pages 18 - 18
1 Jun 2016
Kiran M Jariwala A Wigderowitz C
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The aim of this study was to compare the results of Matti-Russe (MR) procedure and interpositional techniques (IT) in the management of scaphoid non-union. 50 scaphoid non-unions were included in this retrospective study. Demographics, initial management of fracture, location of non-union, time to surgery, procedure done and immobilisation time were recorded. Radiographs were analysed for union and deformity correction. Functional outcome was analysed using the Herbert's grading system. The mean age and time to surgery were 26.7 years and 15.9 months. Twenty-one patients had the MR procedure and twenty-nine patients had interpositional procedures with internal fixation. DISI was present in 17 patients. The mean postoperative change in the scapholunate angle with the MR procedure was 7.9° compared to 8.0° (p>0.05) for the IT procedures. Union rate was 76% for both procedures. The mean follow-up was 9.9 months. Functional results were Herbert 0 or 1 in 42 cases. The only significant prognostic variables were location of non-union and time to surgery. Similar deformity correction was achieved using both IT and MP procedures. MP procedure can be used in the management of scaphoid non-union even in the presence of deformity with good functional results


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XLIV | Pages 16 - 16
1 Oct 2012
Smith E Al-Sanawi H Gammon B St. John P Pichora D Ellis R
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Primary internal fixation of uncomplicated scaphoid fractures is growing in popularity due to its advantages over conventional cast fixation. Performing the procedure percutaneously reduces the risk of infection and soft tissue damage, but can be tricky because of the small size and complex three-dimensional (3D) shape of this bone. Computer-assisted navigation has been an invaluable tool in other pin insertion procedures. This in-vitro study aimed to evaluate two different rendering techniques for our navigation interface: (i) 3D volume rendering of the CBCT image to show digitally-reconstructed radiographs of the anatomy, and (ii) volume-slicing, analogous to CT-images. As the shape of the scaphoid is highly variable, a plastic model of the wrist was constructed in order to provide consistency that would not be possible in a cadaver-based study. The plastic model featured a removable scaphoid such that a new one was replaced between trials. Three surgeons each performed eight trials using each of the two navigated techniques (yielding a total of 48 trials for analysis). Central placement of scaphoid fixation has been linked with mechanical stability and improved clinical outcomes, thus the surgical goal was to place a K-wire to maximise both depth from the surface and length of the drill path. The wire was drilled through the scaphoid, from distal to proximal, allowing for post-trial analysis of the drill path. A ceiling-mounted OptoTrak Certus camera (Northern Digital Inc., Canada) and a floor-mounted isocentric 3D CBCT C-arm (Innova 4100, GE Healthcare, France) permitted a registration transformation between the tracking and imaging systems to be computed preoperatively, before each trial, using a custom calibration device. Optical local coordinate reference bodies were attached to the wrist model and a custom drill guide for tracking with the Certus camera. During each trial, a 3D spin image of the wrist model was acquired, and rendered according to the technique under study. For 3D volume rendering, the spin image was rendered as a digitally-reconstructed radiograph (DRR) that could be rotated in three dimensions. In the planning phase, the surgeon positioned a desired drill path on the images. Anterior-posterior and lateral views of the 3D volume rendering were used for navigation during the drilling phase. The real-time orientation of the drill guide was shown relative to these images and the plan on an overhead. For volume-sliced (VS) navigation, the spin image was volume-rendered and sliced along the principal planes (axial, coronal, sagittal) for planning. A slider interface allowed the surgeon to scroll through the slices in each of the planes, as if they were looking at individual CT slices. Once the desired drill path was positioned, the volume-sliced views were reconfigured to show slices along the oblique planes of the planned path for navigation. Following all trials, model scaphoids with wire intact were imaged using CT with a slice thickness of 0.625 mm. The CT series were segmented and used to construct 3D digital models of the wire and drilled scaphoid. Algorithms were developed to determine the minimum distance from the centerline of the wire and the scaphoid surface, and to compute the length of the drill path. Screw breach should be avoided as it disrupts the articular surface and may lead to a sequela of cartilage deterioration and osteoarthritic changes. The shortest distance measure was extrapolated to assess whether a standard fixation screw (Accutrak Mini, 1.78 mm radius) would have breached the scaphoid surface. There were three screw breaches noted in the 3D DRR trials, while only one occurred using volume-slicing. The minimum distance from the centerline of the wire to the scaphoid surface can also be thought of as a “safe zone” for screw breach. Although no difference in the mean distance (μ) was noted between groups (μ. DRR. = 2.3 mm, μ. VS. = 2.2 mm), the standard deviation (σ) was significantly higher for the DRR trials (σ. DRR. = 0.50 mm, σ. VS. = 0.37 mm, p < 0.1), suggesting a higher reliability of central placement using VS for navigation. In contrast, the length of the drill paths were significantly longer for the DRR trials (μ = 28.7 mm, σ = 0.66 mm) than for VS-navigation (μ = 28.3 mm, σ = 0.62 mm) at p < 0.1. The surgical goal was to pick a path that maximised both the length of the path, as well as the minimum distance from the scaphoid surface. Algorithms were developed to find the paths that would maximise: (i) the length and (ii) the distance from the surface of the model scaphoid used in this study. The maximum possible length was 29.8mm (with a minimum distance of 2.2mm from the scaphoid surface), and the maximum distance was 3.3mm (with a length of 27.5mm). Therefore, the set of optimal drill paths had length > 27.5 mm, and distance > 2.8 mm. Of the DRR-navigated trials, 11 were below the minimum optimal depth, and only one trial was below the optimal length; 13 of the 24 trials (54%) were of both optimal length and depth. Of the VS-navigated trials, nine were below the minimal optimal distance, and four were below the minimum optimal length; 11 out of 24 trials (46%) were within both the optimal length and depth. From this comparative study, we conclude that VS-navigation was superior in locating a central location for the fixation wire, while DRRs were superior in maximising the depth of the drill path. Thus, we propose a hybrid interface, incorporating both volume-slicing and DRRs, in order to maximise the effectiveness of navigation for percutaneous scaphoid pinning


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_16 | Pages 6 - 6
1 Oct 2017
Man WY Davis T
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The aim of our study is to investigate the natural history of scaphoid non-union. Factors affecting the outcome of scaphoid fracture non-union surgery were assessed using data collected retrospectively from 785 cases treated at 18 centres throughout the UK. All cases had undergone this surgery before October 2014, ensuring a minimum period of 2 years between surgery and data collection from the medical records. Smoking status significantly influenced the union rate of 94 proximal pole (non-smokers = 71%, smokers = 44%, p < 0.05) but not waist (non-smokers = 73% non-unions. Type of bone graft did not affect the union rate of the 282 waist nonunions (iliac crest = 69%; non-vascular distal radius = 75% and vascularised distal radius = 70%: P=0.35), but did influence the union rate of the 98 proximal pole nonunions (iliac crest = 58%; non-vascular distal radius = 58% and vascularised distal radius = 82%: P=0.004). Time interval between fracture and non-union surgery did not affect the union rate of 121 proximal pole nonunions (3–6 months = 56%; 6–12 months = 76%; 1–2 years = 69%; 2+years = 54%: P=0.5), but did influence the union rate of 303 nonunions of the waist (3–6 months = 80%; 6–12 months = 82%; 1–2 years = 65%; 2+years = 55%: P=0.02). Non-unions of the proximal pole appear to be influenced by smoking status and bone graft type, whereas non-unions of the scaphoid are influenced by the time to non-union surgery


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XVII | Pages 34 - 34
1 May 2012
Oduwole K Cichy B Dillon J Vusirikala M Wilson J O'Beirne J
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Introduction. It is well established that non-union of the scaphoid requires operative intervention to achieve stable union, restore scaphoid anatomy and prevent further degenerative change. Acutrak screw has been shown to have better biomechanical compression properties than the Herbert screw in the laboratory setting. The aims of the study were to assess the rate of union, the functional outcome and post- operative complications of patients with the two different screw systems. Methods. A retrospective review of the patients who had undergone surgery for non-union of scaphoid treated by a single surgeon. The first group consisted of 61 patients who were treated with Herbert screw and iliac crest bone graft between July 1996 and June 2000. The rate and time to union were assessed clinically and radiologicaly. Their post-operative functional outcome was assessed with modified Mayo wrist score. Results were compared to second group of 71 patients treated with Acutrak screw plus iliac crest bone graft between July 2000 and December 2005. Results. The mean ages of patients (25yrs in Herbert Vs 27yrs in Acutrak) were similar in both groups. The mean time interval between injury and surgery was 12.2months for Herbert group and 17months in Acutrak group. Herbert group had 77% (47) union rate compared to 93% (66) for the Acutrak group. There was persistent nonunion in 14 (22.9%) and 5 (7%) patients in Herbert and Acutrak groups respectively. Functional outcome were excellent in 41% of cases, good in 26% of cases, fair in 22%, and poor in 11 % of cases in Herbert group. For Acutrak group, the outcome score were better with excellent 60% of cases, good in 25%, fair in 10% and poor in 5% of the cases. Wrist fusion was performed in 4 and 1 cases for Herbert and Acutrak group respectively due to progressive wrist pain. Conclusion. Acutrak screw offer better union rate and functional outcome following surgery for scaphoid nonunion


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVIII | Pages 56 - 56
1 Sep 2012
Steiger C Bignion D Valderrabano V Kurzen P
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Purpose. Scaphoid non-unions can result in debilitating wrist problems. This study compared treatment of scaphoid non-unions using either a non vascularised (NVBG) or a vascularised bone graft (VBG). Method. Twenty one cases of scaphoid non-unions were treated by two surgeons between 2005 and 2008 using either a NVBG from the iliac crest or a VBG from the radius based on a 1,2 intercompartmental supraretinacular artery pedicle. Results. Of the 21 cases only 19 were available followed up at a minimum of 3 months with 12 cases available for clinical follow-up 2–5 years postoperatively. Union was achieved in 9 of 11 cases in the VBG group and in 6 of the 8 cases in the NVBG group with no statistically significant difference in average time to union. Wrist range of motion was compared at the time of consolidation and at the follow-up showing no significant difference between the two groups. 11 patients completed the Dash-score and the Mayo-wrist-score with similar results in both groups. Conclusion. This study could not demonstrate any significant differences in clinical and functional outcome at the time of confirmed fracture union or at a late follow-up


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVIII | Pages 51 - 51
1 Sep 2012
White NJ Raskolnikov D Swart E Rosenwasser MP
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Purpose. Although multiple surgical options exist for chronic static scapholunate dissociation, no single procedure has been found to be superior clinically or kinematically. We hypothesize that the reduction and association of the scaphoid and lunate (RASL procedure) is a safe and effective procedure that improves function and alleviates pain in the injured wrist. The purpose of this study is to report long-term follow-up of patients undergoing the RASL procedure over a 20-year period. Method. Between December 1991 and September 2008, the senior author performed 36 RASL procedures for chronic static scapholunate dissociation. This reconstruction involves reduction of the rotational deformity and diastasis between the scaphoid and lunate through a dorsal approach to the wrist. Maintenance of reduction is accomplished with a cannulated, headless, smooth-shafted compression screw directed from the scaphoid to the lunate along the anatomic axis of rotation between the two bones. For the purposes of this study, patients were evaluated by visual analog pain scale (VAS), Disability of the Arm, Shoulder and Hand questionnaire (DASH), SF-36 health survey, physical examination and radiographs. Results. Thirty-two of 36 patients were available for questionnaires and 23 available for questionnaires and physical examination, with an average time to final follow-up of 6.2 years post-operatively. The mean DASH score was 16.6, and other patient-based outcomes showed similarly favorable results. Range of motion was well preserved with 80% of the contralateral flexion-extension arc being maintained in those available for physical examination. Grip strength was well preserved at 90% of the contralateral side. X-rays showed significant decreases in scapholunate gap (p < 0.001) and scapholunate angle (p < 0.001) as compared to preoperative films. In the 32 patients followed, there were 2 treatment failures going on to have salvage procedures for progression to scapholunate advanced collapse deformities. These patients were included in the final analysis. Conclusion. The RASL procedure is a safe and effective treatment for chronic static scapholunate dissociation. It re-aligns the scaphoid and lunate, restores function, reduces pain, and appears to be robust over time


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_19 | Pages 19 - 19
1 Dec 2014
Carides E
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Introduction and Aims:. The surgical treatment of fractures of the scaphoid with delayed presentation or with established non-union pose a formidable challenge with reported failure rates between 15% and 45%. The aim of this study is to report the results of percutaneous versus open fixation with bone grafting of these fractures. Method:. 34 Consecutive patients who underwent surgery between 2009 and 2013 for delayed presentation and established non-union of scaphoid fractures have been reviewed retrospectively. There were 27 males and 7 females with a mean age of 31 years (15 to 66). The mean delay from time of injury to operation was 12 weeks (4 weeks to 11 months) in the percutaneous fixation group and 19 months (5 months to 6 years) in the open fixation group. 19 Patients were treated with percutaneous screw fixation alone and 15 patients underwent open reduction and internal fixation supplemented with autogenous corticocancellous iliac bone graft. The classification of Slade and Dodds (2009) was used as a guide for surgical treatment and the Mini-Acutrak headless compression screw was used as the fixation device in all cases. Results:. Patients underwent final clinical and radiological assessment with plain radiographs 6 months following their surgery. There was one failed union in the percutaneous fixation group and there was one failed union in the open fixation group. One patient in the open fixation group was lost to follow up. No serious complications were recorded in either group. Conclusion:. The success of percutaneous internal fixation for acute fractures of the carpal scaphoid may be extended to include scaphoid fractures with delayed presentation and fractures of the scaphoid with established nonunion. However, appropriate patient selection is necessary to ensure optimal outcomes


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_14 | Pages 9 - 9
1 Jul 2016
Jawalkar H Aggarwal S Bilal A Oluwasegun A Tavakkolizadeh A Compson J
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Scaphoid fractures accounts for approximately 15% of all fractures of hand and wrist. Proximal pole fractures represent 10–20% of scaphoid fractures. Non –operative treatment shows high incidence of non-union and avascular necrosis. Surgical intervention with bone graft is associated with better outcome. The aim of this study was to evaluate the radiological and functional outcome of management of proximal pole scaphoid non-union with internal fixation and bone grafting. We included 35 patients with proximal pole scaphoid non-union (2008–2015). All patients underwent antegrade headless compression screw fixation and bone grafting at King's College Hospital, London (except one, who was fixed with Kirschner wire). 33 patients had bone graft from distal radius and two from iliac crest. Postoperatively patients were treated in plaster for 6–8 weeks, followed by splinting for 4–6 weeks and hand physiotherapy. All the patients were analysed at the final follow-up using DASH score and x-rays. Mean age of the patients was 28 years (20–61) in 32 men and 3 women. We lost three patients (9%) to follow up. At a mean follow up of 16 weeks (12–18) twenty three patients (66%) achieved radiological union. All patients but three (91%) achieved good functional outcome at mean follow up of 14 weeks (10–16). A good functional outcome can be achieved with surgical fixation and bone graft in proximal pole scaphoid fractures non-union. Pre-operative fragmentation of proximal pole dictates type of fixation (screw or k wire or no fixation). There was no difference in outcome whether graft was harvested from distal radius or iliac crest


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XIX | Pages 14 - 14
1 May 2012
Maclean A Howells N Blewitt N
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Scaphoid injuries remain a challenge in both diagnosis and subsequent management. Untreated scaphoid non-union leads to inevitable osteoarthritis. Non-unions are picked up via an established management pathway in out trust and treated surgically with a standardised technique of non-vascularised bone grafting and retrograde screw fixation. Patients that underwent primary screw fixation and grafting for scaphoid non-union between 2004-2008 were reviewed. These patients were followed up clinically and radiologically. They were assessed for time to union, complications, DASH score, patient satisfaction and return to work. In addition comparison was made between the use of Herbert screw and Twinfix screw fixation and between tricortical iliac crest graft and corticocancellous distal radial bone graft. Forty-two consecutive patients underwent surgery of which 35 (83%) were available for follow up. Mean follow up was 39 months (range 13-72). 31 (89%) patients had gone on to radiological union. Of those united the mean DASH score was 11. Mean time to union was 4.4 months (range 2-15 95% CI 3.3 – 5.5). 95% of patients were satisfied with their operation and would recommend it to a friend in the same situation. No significant difference in outcomes were identified between Herbert screw and Twinfix screw fixation or between iliac crest or distal radial bone grafting techniques. This study has shown encouraging results for an established protocol for management of scaphoid non-union. Outcomes are as a good as any published comparable series in the literature and provide further support to the use of this technique


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXIX | Pages 137 - 137
1 Sep 2012
Singh H Taub N Dias J
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Background. Scaphoid fractures with displacement have a higher incidence of nonunion and unite in a humpback position that can cause pain and reduced movement, strength and function. The aim of this study is to review the evidence available and establish the risk of nonunion associated with management of displaced scaphoid fractures in a plaster cast. Methods. Electronic databases were searched using the MeSH (Medical Subject Headings) controlled vocabulary (scaphoid fractures, AND'd with explode displaced, or explode nonunion, or explode non-healing or explode cast immobilisation, or explode plaster, or explode surgery). As no randomised or controlled studies were identified, the search was limited to observational studies based on consecutive cases with displaced scaphoid fractures treated in a plaster cast. The criterion for displacement was limited to gap or step of more than 1mm. The ‘random effects’ calculation was used to allow for the possibility that the results from the separate studies differ more than would be expected by chance. Results. Of the 27 articles identified, seven studies were eligible for the meta-analysis with a total of 1401 scaphoids. 93% (1311 scaphoids) of these scaphoid fractures healed in a plaster cast. 207 (15%) of all scaphoid fractures showed displacement of at least 1mm (Gap/step) between fracture fragments. Nonunion was identified in 18% (37/207) of displaced scaphoid fractures treated in a plaster cast. The pooled odds ratio of fracture nonunion between the displaced and undisplaced groups was five times higher with fracture displacement (pooled odds ratio: 5.5, 95%CI: 2.5–12.3; p=0.00, I. 2. =54.6%). The pooled relative risk of fracture nonunion was 4.4 (95%CI: 2.3–8.7; p=0.00 I. 2. =54.3%). Conclusions. Displaced fractures of scaphoid have a four times higher risk of nonunion when treated in a plaster cast and the patients should be advised of this potential risk