Scaphoid Fracture Fixation in a Nonunion Model: A Biomechanical Study Comparing 3 Types of Fixation

Union rate and clinical outcomes of second-try scaphoid reconstructions after failed primary scaphoid osteosynthesis or reconstruction. A retrospective, single-center cohort study of 52 patients

Introduction

Scaphoid non-union after failed primary surgery presents significant therapeutic challenges.

Methods

In this retrospective study, 52 patients (50 males; mean age 29.5 years) underwent secondary reconstructions (2009-2020) for proximal pole (38.5%, n = 20) and waist non-unions (61.5%, n = 32). Treatments included non-vascularized iliac crest grafts (17 patients), vascularized pedicled distal radius grafts (26), and free medial femoral condyle flaps (9). Union and scaphoid alignment were assessed by CT, while carpal alignment and arthrosis were evaluated using radiographs. Statistical analysis employed chi-square, Fisher's exact, Mann-Whitney U, and McNemar tests (R v4.4.2; p ≤ 0.05).

Results

Union rates differed significantly between proximal pole (40%, 8/20) and waist non-unions (68.75%, 22/32; p = 0.04). Graft type (p = 0.616), osteosynthesis method (p = 0.827), age (p = 0.095), smoking (p = 0.582), avascular necrosis (p = 0.42), and prior surgeries (p = 0.974) showed no significant association with union. Proximal pole non-unions with AVN trended toward lower union (22.2% vs. 54.5% without AVN), though this was not statistically significant. In patients achieving union, scaphoid humpback deformity was corrected in 9/15 cases (p = 0.0348), and dorsal intercalated segment instability improved significantly (p = 0.0143). Functionally, the union group had an average extension-flexion of 112° (81% of the healthy wrist) and radial-/ulnar adduction of 40° (72% of the unaffected wrist), with grip strength averaging 42 kg (range 25.2-59.7) and a DASH score of 11 (range 0-67). The non-union group showed 114° extension-flexion (91% of the unaffected wrist) and 38° ulnar/radial abduction (78% of the healthy wrist), with grip strength averaging 46 kg (range 37.6-59.3; 89% of the unaffected wrist) and a DASH score of 10 (range 3-33).

Discussion

Secondary scaphoid reconstruction demonstrates location-dependent success. The decision between secondary reconstruction, which aims to restore anatomical integrity, and salvage procedures, which prioritize predictable outcomes, hinges on balancing union potential, functional results, and patient preferences. A tailored approach remains essential to align treatment goals with individual needs.

The Biomechanical Stability of a Single Headless Compression Screw Construct to Fix Scaphoid Waist Fractures

BACKGROUND

Scaphoid fracture fixation using a single headless compression screw (HCS) may permit unacceptable rotation at the fracture site. This study aimed to assess the biomechanical stability of a single HCS construct to fix scaphoid waist fractures.

QUESTIONS/PURPOSES

(1) Does a single HCS provide rotational stability? (2) What degree of rotation is found at the central axis of a scaphoid without fixation?

METHODS

In eight fresh frozen cadavers, two parallel K-wires were placed in the scaphoid to mark rotation and an osteotomy was created at the scaphoid waist. To determine whether rotation was present between the proximal and distal poles, radiographs of the wrist at terminal range of motion (ROM) were reviewed for relative change in wire position. The fracture was then reduced, and an HCS was then advanced across the fracture; rotation was again evaluated. Rotation was quantified in the group without fixation using a sensor that measured angular rotation.

RESULTS

Before screw fixation, interfragmentary rotation was found to average 22.5° during flexion/extension, 19.0° during pronation/supination, and 34.0° during radial/ulnar deviation around the central axis. The radiographs after osteotomy demonstrated rotation in all specimens. After fixation with an HCS, radiographs demonstrated relative rotation of the two halves of the scaphoid in all ROMs for all specimens, except flexion for one specimen.

DISCUSSION

Internal angular tension was observed within the scaphoid, and rotation of 20° to 30° was noted around the central axis during simulated ROM mimicking nonsurgical treatment. A single HCS failed to prevent fragment-relative rotation at the fracture site.

What Is the Optimal Method of Fixation for Scaphoid Nonunion Relative to the Location of the Lesion?

INTRODUCTION

Scaphoid nonunion is a typical complication of scaphoid fractures, with the nonunion rate varying by the location of the scaphoid. The current widely used method for treating scaphoid nonunion, which is challenging for surgeons, is the headless compression screw (HCS). Various surgical approaches, such as the scaphoid plate, have been proposed to address the problem of screw fixation; however, no consensus exists regarding the optimal treatment method. This study focused on analyzing appropriate treatment methods based on the anatomical location of the scaphoid nonunion.

METHODS

Ninety-seven patients with scaphoid nonunion were treated between 2008 and 2023. All patients underwent treatment using 1 HCS or scaphoid volar locking plate with nonvascularized bone graft from the distal radius depending on the scaphoid's location. The scaphoid angle and bone union were confirmed using radiological examinations. The clinical evaluations included range of motion, pain, grip strength, and functional wrist scores.

RESULTS

Fifty-seven patients were included in the final analysis. In the screw group, 26 patients (26/42 [62%]) obtained a bone union, and all 15 patients (15/15 [100%]) in the plate group obtained a union ( P = 0.005). In the waist group, 16 patients with screw (16/25 [64%]) and 8 using a plate (8/8 [100%]) showed bony healing. In the proximal group, 3 patients with HCS (3/9 [33%]) and 4 using plate (4/4 [100%]) showed bone union. In the distal group, 7 patients with a screw (7/8 [87%]) and 3 with the plate (3/3 [100%]) showed bone union. Significant differences were found in the waist ( P = 0.047) and proximal groups ( P = 0.026), but not in the distal group ( P = 0.521). All groups showed improved radiological angles associated with the scaphoid and better clinical outcomes postoperatively.

CONCLUSIONS

Plate fixation was overall superior to screw fixation for scaphoid nonunion, especially in the waist and proximal poles, providing better union rates and stability. For the distal group, both methods are effective, with the choice depending on the surgeon's expertise and patient factors. The results highlight the importance of the lesion's anatomical location in selecting the appropriate fixation method.

Advances in the Treatment of Hand and Wrist Injuries in the Elite Athlete

Caring for hand and wrist injuries in the elite athlete brings distinct challenges, with case-by-case decisions regarding surgical intervention and return-to-play. Metacarpal fractures, thumb ulnar collateral ligament tears, and scaphoid fractures are common upper-extremity injuries in the elite athlete that can be detrimental to playing time and future participation. Treatment should therefore endure the demand of accelerated rehabilitation and return-to-activity without compromising long-term outcomes. Fortunately, the literature has supported emerging management options that support goals specific to the athlete. This review examined the advances in surgical and perioperative treatment of metacarpal fractures, thumb ulnar collateral ligament injuries, and scaphoid fractures in the elite athlete.

In vivo non-contact regions of proximal scaphoid in six extreme wrist positions

INTRODUCTION

Fractures of the scaphoid are the most common carpal injuries, account for 80-90% of all carpal fractures. 5-15% nonunion of scaphoid fractures were reported even with adequate primary treatment, which probably progresses to osteoarthritic changes several decades later. Researches regarding to scaphoid physiological characteristic in vitro and in vivo and kinds of trials in clinical practice are being kept on going, which contribute much to our clinical practice. With the advancing wrist arthroscopy, 3D-print patient-specific drill guide, and intraoperative fluoroscopic guidance, dorsal approach (mini-invasive and percutaneous technique) is being popular, through which we can implant the screw in good coincidence with biomechanics and with less disturbing tenuous blood supply of the scaphoid. Investigating the noncontact area of the dorsal proximal scaphoid in different wrist positions can facilitate preoperatively estimating insert point of the screw.

MATERIALS AND METHODS

Eight volunteers were recruited to accept CT scans in six extreme wrist positions. The images of DICOM mode were imput into the Mimics analytical system, the segmented scaphoid, lunate and radius were exported in mode of ASCII STL and were opened in the software of Geomagic studio. We created four planes based on anatomic markers on the surface of the radius and scaphoid to confine the proximal scaphoid to form the so-called non-contact regions. We measured and compared the areas in six targeted positions.

RESULTS

Amidst six extreme wrist positions, area of the non-contact region in extreme dorsal extension (59.81 ± 26.46 mm2) was significantly the smallest, and it in extreme palmar flexion significantly was largest (170.51 ± 30.44 mm2). The non-contact regions increased in order of dorsal extension, supination, ulnar deviation, radial deviation, pronation and palmar flexion. As for two-group comparison, the non-contact region showed significantly larger (p < 0.05) in palmar flexion than the others except for in pronation individually, and in radial deviation (p < 0.05) than in dorsal extension.

CONCLUSIONS

Sufficient space was available for the screw started from the dorsal approach despite the wrist positions.

A comparative study of volar locking-plate fixation with corticocancellous and pure cancellous bone grafts for scaphoid nonunion with dorsal intercalated segmental instability secondary to scaphoid humpback deformity

INTRODUCTION

Bone grafts for scaphoid nonunion with deformity include cortcicocancellous or pure cancellous bone grafts. This study compared the outcomes between two types of bone grafts when employing a volar locking-plate in patients with scaphoid nonunion with dorsal intercalated segmental instability (DISI).

PATIENTS AND METHODS

This retrospective study included 34 patients with scaphoid nonunion and DISI due to humpback deformity treated between March 2017 and January 2022. Two types of bone grafts were obtained from iliac crest. Twenty of the corticocancellous (CC) group underwent a wedge-shaped graft, while 14 patients of the pure cancellous (C-only) group received graft chips. In both groups, a 1.5-mm anatomically pre-contoured locking plate was used for fixation. Radiographic evaluations included the union rate and carpal alignment including scapholunate angle (SLA), radiolunate angle (RLA), intrascaphoid angle (ISA) and scaphoid height to length ratio (HLR). Clinical assessments encompassed wrist range-of-motion, grip strength, and patient-reported outcomes.

RESULTS

Nineteen of the 20 patients in the CC group and 12 of the 14 patients in the C-only group respectively, achieving osseous union. The mean follow-up period in CC group was 14.7 (range, 12 ∼ 24) months and that in C-only group was 12.6 (range, 12 ∼ 15) months. Postoperatively, there were no significant intergroup differences of radiographic parameters including SLA (CC; 49.9° ± 6.7° vs. C-only; 48.9° ± 3.5°, P = 0.676), RLA (1.7° ± 6.4° vs. 2.4° ± 3.3°, P = 0.74), ISA (36° ± 7.5° vs. 36.6° ± 12.2°, P = 0.881), and HLR (0.54 ± 0.09 vs. 0.53 ± 0.05, P = 0.587). Clinical outcomes, including the flexion-extension arc (137° ± 30° vs. 158° ± 33°, P = 0.122), grip strength (93.4 % ± 15.4% vs. 99.5 % ± 16.7 %, P = 0.39), Quick Disabilities of the Arm, Shoulder, and Hand scores (11.2 ± 8.3 vs. 12.5 ± 7.7, P = 0.74) and Mayo Wrist Scores (81.2 ± 13.1 vs. 89 ± 11.4, P = 0.242) also showed no significant intergroup differences.

CONCLUSIONS

Volar locking-plate fixation with pure cancellous bone grafts achieved outcomes comparable to those achieved with corticocancellous bone grafts in scaphoid nonunion with deformity, possibly due to the biomechanical advantages of the volar plate to provide structural supports.

Finite Element Analysis of Postoperative Stability of Transverse Scaphoid Waist Fracture

Background and Purpose

Scaphoid waist fractures are often stabilised with compression screws, Kirschner wires (K-wires), or a combination of both. While clinical and bio-mechanical studies evaluating their utility are available, the ideal configuration of implant that would provide adequate stability to permit early use of the hand is debatable. We examined configurations of a single screw, one screw along with a K-wire, and two K-wires used for a transverse scaphoid waist fracture fixation aiming to assess the stability provided by each in the immediate postoperative period.

Methods

Computer-aided design (CAD) models of the scaphoid, K-wire, and headless compression screw were created. A transverse fracture was created at the scaphoid waist, and the CAD models of the screw and K-wire were used to fix the fracture in different configurations in a distal to proximal direction. Finite Element Analysis (FEA) was used to examine the strength of configurations when they were subjected to compression and distraction forces. The total maximum deformation (TDef) and factor of safety (FoS) for each configuration were calculated and used as indirect indicators of postoperative stability.

Results

When a single screw was used, the configurations with the screw directed posteriorly from either centre or anterior had the best combined TDef and FoS values. For one screw and one K-wire, the configuration with screw and K-wire parallel to each other with the screw located along the long axis in the AP projection and anterior to the K-wire in the lateral projection had the best combined TDef and FoS values. When using two K-wires, configurations with the two wires diverging proximally on the lateral projection had the best combined TDef and FoS values.

Conclusions

When fixing a transverse scaphoid waist fracture with a single screw, the screw directed posteriorly from either the centre or anterior aspect of the distal pole has the best stability, a parallel configuration has the best stability when fixing it using a screw and a K-wire, and divergent configuration has the best stability when fixing it with two K-wires only.

Two Parallel Headless Compression Screws for Scaphoid Fractures: Radiographic Analysis and Preliminary Outcome

BACKGROUND

Despite surgical fixation, the scaphoid nonunion rate remains at 3% to 5%. Recent biomechanical studies have demonstrated increased stability with 2-screw constructs. The objective of our study is to determine the preliminary union rate and anatomic feasibility of 2-screw surgical fixation for scaphoid fractures.

METHODS

This study is a retrospective case series of 25 patients (average age 32 years) with scaphoid fractures treated with 2 parallel headless compression screws (HCS). Postoperative evaluation included Mayo Wrist Score (MWS), range of motion, time to union, and return to activity. Bivariate analysis for gender and Pearson correlation coefficient for body size (height, weight, and body mass index) was conducted against radiographically measured scaphoid width, screw lengths, and the distance between the 2 screws.

RESULTS

All fractures healed with an average time to union of 9.9 weeks (median 7.6 weeks; range: 4.1-28.3). The mean MWS was 93.3 (range: 55-100), with 3 complications (12%), one of which affected the outcome of the surgery. The bivariate analysis demonstrated that the female gender was associated with significantly smaller scaphoid width (P = .004) but a similar distance between the 2 screws (P = .281). The distance between the 2 screws and the body size demonstrated a weak-to-no correlation.

CONCLUSIONS

The 2-screw construct for scaphoid fracture achieved a favorable union rate and clinical outcome. Gender was the only variable significantly associated with scaphoid width and screw length. The distance between the screws was constant regardless of gender and body size, indicating that the technique for parallel screw placement can remain consistent.

TYPE OF STUDY

Therapeutic.

LEVEL OF EVIDENCE

Level IV.

Rethinking Scaphoid Fixation

Scaphoid fixation, whether for acute injuries or nonunion, is made challenging by the small and intra-articular nature of the most commonly fractured carpal bone. The purpose of this article is to review the techniques to simplify scaphoid fixation and to optimize healing and early return to activity.

Scaphoid Plate Osteosynthesis in Complex Fractures and Wrist Trauma: A Case Series

Introduction Treatment of scaphoid fracture is challenging due to its unique blood supply and geometry. Traditionally, a headless compression screw is the standard treatment for unstable scaphoid fracture. Some fractures are complex, for example, comminution with bone loss. A scaphoid plate is an option in these difficult fractures providing adequate rotational stability. Aim To share our experience in using scaphoid plates in complex wrist trauma and comminuted fractures. Method and material Complex wrist trauma involving scaphoid fractures that were comminuted and multi-fragmentary fractures treated with plate osteosynthesis were retrospectively reviewed between July 2019 and September 2021. Patient demographic data, preoperative radiographs, CT scans, pain, wrist range of motion, and fracture union rate to union were reviewed. Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH®) score was recorded at 1-year postoperative follow-up.  Results Nine patients associated with complex wrist trauma were included in this case series. The mean follow-up was 2.5 years (13-30 months). The union rate was 100%. The mean arc of motion was 105° (95-110°). QuickDASH® score was 19.96 at 1-year postoperative follow-up. Four patients had good outcomes, four satisfactory, and one poor outcome. One hardware complication was observed which was the impingement of the plate proximally over the articular surface of the distal radius. Conclusion A scaphoid plate is a reliable option for treating complex and difficult fractures. It provides adequate stability, especially in comminution, bone loss, or multi-fragmentary fractures which are not amendable using other fixation methods. We recommend the expansion of plate osteosynthesis beyond scaphoid nonunion into complex wrist trauma.

Scaphoid fracture and nonunion: new directions

The scaphoid is the largest of the carpal bones, articulating with both proximal and distal carpal rows. If scaphoid fractures are not appropriately diagnosed and treated, there is a risk of nonunion, osteonecrosis and degenerative arthritis. Operative management of the scaphoid fracture is primarily determined by the fracture location and amount of displacement. There is increased momentum for dual screw fixation constructs, intended to provide greater stability and reduce the risk of nonunion. Our current practice is to utilize two screws without graft as a first-line treatment for scaphoid nonunion with or without humpback deformity and cyst formation. This review will discuss the management of acute scaphoid fractures and the treatment of nonunion.

Fixation Techniques for Scaphoid Nonunion

Scaphoid fractures are common injuries with high risk of nonunion. Various fixation techniques exist for managing scaphoid nonunions, including Kirschner wires, single or dual headless compression screws, combination fixation techniques, volar plating, and compressive staple fixation. The indication for each fixation technique varies depending on the patient, type of nonunion, and clinical scenario.

Volar Plating of Scaphoid Fractures: A Retrospective Case Series

BACKGROUND

The purpose of this study was to evaluate the rate of union of scaphoid fractures managed with volar plating and assess postoperative complications.

METHODS

Retrospective consecutive case series of 28 patients with scaphoid fractures, 9 acute and 19 chronic nonunions, undergoing surgical fixation with volar scaphoid plating by a single surgeon between 2013 and 2019. Patients were followed up for a minimum of 3 months with scaphoid bony union being confirmed on radiograph or computed tomography. Postoperative complications and need for plate removal were recorded.

RESULTS

Overall union rate of 96% with all 19 chronic nonunions demonstrating radiological union and 1 of 9 acute fractures not uniting and requiring revision surgery. The only postoperative complication identified was symptomatic plate impingement which necessitated plate removal in 57% of cases.

CONCLUSIONS

This case series demonstrates volar plating of scaphoid fractures can be used as an alternative technique to achieve union.

Double screw versus angular stable plate fixation of scaphoid waist nonunions in combination with intraoperative extracorporeal shockwave therapy (ESWT)

INTRODUCTION

Over the past years, different fixation techniques focused on rotational stability in order to increase stability and stimulate union rates. Additionally, extracorporeal shockwave therapy (ESWT) has gained importance in the treatment of delayed and nonunions. Purpose of this study was to compare the radiological and clinical outcome of two headless compression screws (HCS) and plate fixation in scaphoid nonunions, in combination with intraoperative high energy ESWT.

MATERIALS AND METHODS

Thirty-eight patients with scaphoid nonunions were treated by using a nonvascularized bone graft from the iliac crest and stabilization with either two HCS or a volar angular stable scaphoid plate. All patients received one ESWT session with 3000 impulses and energy flux per pulse of 0.41 mJ/mm² intraoperatively. Clinical assessment included range of motion (ROM), pain according to the Visual Analog Scale (VAS), grip strength, disability of the Arm Shoulder and Hand Score, Patient-Rated Wrist Evaluation Score, Michigan Hand Outcomes Questionnaire and modified Green O'Brien (Mayo) Wrist Score. To confirm union, a CT scan of the wrist was performed.

RESULTS

Thirty-two patients returned for clinical and radiological examination. Out of these, 29 (91%) showed bony union. All patients treated with two HCS compared to 16 out of 19 (84%) patients treated by plate showed bony union on the CT scans. The difference was not statistically significant. However, at a mean follow-up interval of 34 months, no significant differences could be found in ROM, pain, grip strength and patient-reported outcome measurements between the two HCS and plate group. Height-to-length ratio and capitolunate angle improved significantly in both groups compared to preoperative.

CONCLUSIONS

Scaphoid nonunion stabilization by using two HCS or angular stable volar plate fixation and intraoperative ESWT results in comparable high union rates and good functional outcome. Due to the higher rate for a secondary intervention (plate removal), HCS might be preferable as first choice, whereas the scaphoid plate fixation should be reserved for recalcitrant (substantial bone loss, humpback deformity or failed prior surgical intervention) scaphoid nonunions.

Arthroscopic treatment of unstable scaphoid fracture and nonunion with two headless compression screws and distal radius bone graft

BACKGROUND

The treatment of unstable scaphoid fracture and nonunion remains a challenging problem for hand surgeons. Minimally invasive treatment has become the preferred method of treatment.

PURPOSE

This study introduces the arthroscopic technique with two headless compression screws (HCS) fixation and distal radius bone grafting for the treatment of unstable scaphoid fracture and nonunion, aiming to evaluate its clinical and radiological outcomes.

METHODS

It was a retrospective study. From January 2019 to February 2021, a total of 23 patients were included in the current study. Among them, 13 patients with unstable scaphoid fracture underwent arthroscopic treatment with two HCS; 10 patients with scaphoid nonunion underwent arthroscopic treatment with two HCS and a distal radius bone graft. The range of motion of the wrist, visual analog scale (VAS), grip strength, the Modified Mayo Wrist Score (MMWS), the Patient-Rated Wrist Evaluation (PRWE) score, and the Disability of the Arm, Shoulder and Hand (DASH) score were collected at preoperatively and the final follow-up. A computed tomography scan of the wrist was performed on each patient to analyze for union and postoperative osteoarthritis during the follow-up period.

RESULTS

Significant improvement was only observed in wrist extension. Clinical outcomes including grip strength, VAS pain score, MMWS, PRWE score, and DASH score were significantly improved at the final follow-up. In the subgroup analysis, both patients stabilized with either two HCS or a distal radius bone graft and two HCS have improved clinical outcomes after surgery, respectively. All patients achieved union. No screw fixation failure occurred, and no other postoperative complication was observed in any of the patients.

CONCLUSIONS

The arthroscopic technique with two-HCS fixation and distal radius bone grafting is a reliable and effective technique for the treatment of unstable scaphoid fracture and nonunion, providing satisfactory union rates and clinical outcomes.

Clinical outcomes of double-screw fixation with bone grafting for displaced scaphoid nonunions: A series of 21 cases

Purpose

This study reports the clinical outcomes of double-screw fixation with bone grafting for displaced scaphoid nonunions.

Patients and methods

This study was a retrospective survey. From January 2018 to December 2019, 21 patients with displaced scaphoid fractures underwent open debridement and two headless compression screw fixation with bone grafting. The preoperative and postoperative lateral intrascaphoid angle (LISA) and scapholunate angle (SLA) were recorded. Preoperative and postoperative grip strength (% of the healthy side), active range of motion (AROM), visual analogue scale (VAS), and patient-rated wrist evaluation (PRWE) scores at the final follow-up were obtained for all patients for comparison.

Results

Patients were treated for an average of 38.3 months (range 12-250) after the injury. The average time of postoperative follow-up was 30.5 months (range 24-48). All fractures achieved union at a mean of 2.7 months (range 2-4) after surgery, and 14 scaphoids of 21 patients (66.7%) healed by 8 weeks. CT scans showed no evidence of cortical penetration of either screw in all patients. There was a statistically significant improvement in AROM, grip strength, and PRWE. No complications occurred in this study, and all patients returned to work.

Conclusion

This study indicates that double-screw fixation with bone grafting is an effective technique for treating displaced scaphoid nonunions.

A Comparison Between Robotic-Assisted Scaphoid Screw Fixation and a Freehand Technique for Acute Scaphoid Fracture: A Randomized, Controlled Trial

PURPOSE

We compared robotic-assisted scaphoid screw fixation to conventional technique in terms of accuracy, surgical times, radiation exposure, and clinical outcomes, including range of motion, grip strength, functional score, and complications.

METHODS

This study was a registered, prospective, randomized, controlled trial. From May 2019 to December 2019, 1 surgeon performed 18 robotic-assisted and 18 conventional scaphoid screw fixations and these patients were eligible for participation in this study. Surgical time, including the time of the overall procedure, set-up time, and time for ideal guidewire placement, was recorded. The number of guidewire attempts also was recorded. All patients were evaluated clinically and radiographically at follow-up with respect to the severity of pain, wrist motion, grip strength, complications, and Mayo modified wrist score.

RESULTS

The average set-up time and overall time of the procedure were longer in the robotic-assisted than in the conventional groups, while the mean guidewire insertion time and the mean guidewire attempts was less in the robotic-assisted group than that of the conventional group. The overall radiation exposure was lower in the robotic group.

CONCLUSIONS

Robotic-assisted technique provided a useful tool to improve implantation accuracy and shorten radiation exposure. Additional cost and prolonged duration of surgery without evidence of improved clinical scores may limit widespread acceptance of this technique.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic II.

Double-Screw Osteosynthesis in an Unstable Scaphoid Fracture Model: A Biomechanical Comparison of Two Screw Configurations

PURPOSE

Although there is evidence that a single headless compression screw is sufficient for fixation of most scaphoid fractures, double-screw osteosynthesis has been shown to result in higher failure strength and stiffness than a single screw. However, the biomechanical effect of different screw configurations has not been determined.

METHODS

A standardized unstable fracture model was produced in 28 cadaveric scaphoids. Specimens were randomly allocated to 1 of 2 fixation groups using 2 internal compression screws positioned in either the sagittal or coronal plane. A specimen-specific 3-dimensionally-printed customized screw placement and osteotomy device was developed using computer-aided design-generated models derived from computed tomography scan data of each individual scaphoid. Load to failure and stiffness of the repair constructs were evaluated using a mechanical testing system.

RESULTS

There were no significant differences in size, weight, and density between the scaphoid specimens. The average distance between screws was significantly greater in the sagittal group than in the coronal group. There were no significant differences between the coronal and sagittal aligned double screws in load to 2 mm displacement (mean coronal 180.9 ± 109.7 N; mean sagittal 156.0 ± 85.8 N), load to failure (mean coronal 275.9 ± 150.6 N; mean sagittal 248.0 ± 109.5 N), stiffness (mean coronal 111.7 ± 67.3 N/mm; mean sagittal 101.2 ± 45.1 N/mm), and energy absorption (mean coronal 472.6 ± 261.4 mJ; mean sagittal 443.5 ± 272.7 mJ).

CONCLUSIONS

There are no significant biomechanical differences between the sagittal or coronal aligned double headless compression screws in a scaphoid fracture model with bone loss.

CLINICAL RELEVANCE

In cases where double-screw fixation of the scaphoid is being considered, the placement of double screws can be at the discretion of the surgeon, and can be dictated by ease of access, surgical preference, and fracture orientation.

Wrist angle measurements in predicting the presence of a displaced scaphoid fracture

PURPOSE

Early diagnosis and treatment of scaphoid fractures is critical to achieve union and prevent wrist degenerative arthritis. Plain radiographic measurements can guide the early approach to suspected fractures. Specifically, the ability to predict fracture or fracture stability from plain radiographs may allow the traumatologist to expand initial referral to three-dimensional imaging. We evaluated the ability of four measured angles to predict presence of a scaphoid fracture and stability.

METHODS

Fifty patients with a scaphoid fracture and 50 patients without fracture were evaluated for the cortical ring sign, scapho-lunate gapping, lateral scapholunate (SL), radio-scaphoid (RS), radio-lunate (RL), and radio-capitate (RC) angles by two-blinded observers.

RESULTS

Measurement of an increased SL interval was associated with the presence of a scaphoid fracture as diagnosed on three-dimensional imaging [odds ratio (OR) 3.0, confidence interval (CI) 1.53-5.87, p =  < 0.01]. The measured RL angle was associated with fracture displacement (OR 1.13, 95% CI 1.02-1.25, p = 0.02).

CONCLUSIONS

Scapholunate gapping on plain radiographs in the context of a clinically suspected scaphoid fracture should increase suspicion for a fracture and may prompt earlier 3-dimensional imaging, while the presence of an abnormal radiolunate angle should increase wariness for instability and can be used in preoperative planning.

Locking plate osteosynthesis of scaphoid nonunion with severe bone defects: a case series

The treatment of scaphoid nonunion can be challenging with increasing defect size. We evaluated the outcome of scaphoid nonunion with a substantial bone defect treated with a multidirectional locking plate combined with cancellous bone grafting only. Thirteen patients with significant osseous defects measuring 6 mm or more suffering from primary nonunion without treatment (n = 6) or recalcitrant nonunion following Herbert screw osteosynthesis (n = 7) were treated and reviewed retrospectively. The stabilization was performed after debridement, autologous cancellous bone grafting and volar locking plate osteosynthesis. After a mean follow-up period of 12 months, 12 of the 13 patients achieved successful unions with a free range of motion and complete remittance of pain in everyday activity. The mean scapholunate angle decreased from 59.7° ± 11 to 43.9° ± 5 (effect strength d:1.7, p < 0.00001), scaphoid humpback deformity angle from 58.9° ± 8 to 45.1° ± 8 (d:1.8, p < 0.0001), whereas strength of the injured hand increased from 36.4 kg ± 10 to 42.4 kg ± 9 (d:1.4, p < 0.0001). One nonunion persisted without fragment dislocation receiving revision after 1 year. Thus, locking plate osteosynthesis with cancellous bone grafting is a valid alternative in scaphoid nonunions with extensive bone defects. Additionally, stable retention of the fragments prevents dislocation even in delayed or persistent nonunion. Further prospective studies are required to confirm these findings.

Cannulated compression screw with versus without two K-wire fixation for treatment of scaphoid waist fracture nonunion

Purpose

This study aims to introduce the “tripod” technique using cannulated compression screw and two anti-rotational K-wires for treatment of unstable scaphoid waist fracture nonunion, and to compare it with the single cannulated screw fixation technique in term of scaphoid union and surgical outcomes.

Methods

It was a retrospective study. From January 2014 to March 2020, 103 consecutive patients with scaphoid waist fracture nonunion treated with the tripod fixation and bone grafting (n = 45) or with single cannulated compression screw and bone grafting (n = 58) were included. All the procedures were performed by the same hand surgery team, and autologous cortico-cancellous radius bone graft was used for bony reconstruction. The minimal follow-up period was 12 months. The union rate and the time to union, range of motion (ROM), grip strength, Visual Analogue Scale (VAS), Quick Disabilities of the Arm, Shoulder and Hand (DASH) score and modified Mayo Scores at the last visit were compared.

Results

In tripod fixation group, bony union was achieved in all patients at the mean of 14.8 ± 3.8 weeks, while in the single cannulated screw fixation group the bony union rate was 94.8% (55/58) and the time to union was 17.6 ± 3.6 weeks. The difference of time to union was statistically significant (p = 0.027), but not for bony union rate (p = 0.122). At the last visit, no significant difference was found with respect to any clinical and radiographic outcome measures (all p > 0.05). The overall rate of complications was not significantly different between two groups (15.6% vs 10.3%, p = 0.430).

Conclusions

Tripod fixation technique with headless compression screw and two K-wires is a safe and effective technique for treatment of scaphoid nonunion fixation and can be considered to use in practice, especially for those potentially rotationally unstable cases.

Scaphoid plating for recalcitrant scaphoid fractures: a systematic review

We conducted a systematic review of scaphoid plating for recalcitrant scaphoid fractures using EMBASE, Pubmed, Cochrane and MEDLINE. Thirteen studies were included. Ninety-three per cent of cases reported were male with a mean age of 27 years. Bony union was reported in eleven studies and achieved in 72% to 100% of cases. Scaphoid plates showed no significant difference in union incidence compared with headless compression screws. Mean removal incidence of plates was 21%. Postoperative flexion-extension arc was 119°. Grip strength improved by 14% postoperatively over that before surgery. There was a general improvement in patient-reported outcome measures. Eighty-six per cent of reported participants returned to their previous work. In these clinical reports, plates frequently required removal more frequently than headless compression screws.

Hot Topics in Hand and Wrist Surgery

The field of hand surgery continues to evolve in new and exciting directions. Advances in diagnosis and management for common complaints and complex injuries allow higher-level care, while still being cognizant of the cost of health care delivery. Indications and protocols for past paradigm shifts, such as volar locked plating for distal radial fractures, continue to be honed, and the outcomes seen for modern flexor tendon repairs are impressive. Open questions remain, but promising results for scaphoid nonunion surgery and peripheral nerve reconstruction with processed allograft will continue to shed light on these unsolved problems.

Robot-assisted double screw fixation of minimally displaced scaphoid waist fracture nonunions or delayed unions without bone graft

We retrospectively reviewed 12 minimally displaced fractures of the scaphoid waist in 12 patients who developed delayed or nonunions with or without conservative treatment. Mean time between injury and surgery was 6 months (range 3-12). The fractures were stabilized with double screws, which were percutaneously inserted with robot assistance, and without bone grafting. All fractures united at a mean of 8 weeks (range 6-10) after surgery. The patients were followed-up at 6 months and 1 year. The patients recovered good wrist function. No major postoperative complications were reported, and the patients returned to their usual level of activity. Robot assistance gave a high degree of accuracy when placing the cannulated screws since only two attempts were needed for correct placement of the guide wires. We explain the high union incidence by patient selection, good stabilization and not disturbing the vascular supply.Level of evidence: IV.

Clinical Outcomes of Double-Screw Fixation with Autologous Bone Grafting for Unstable Scaphoid Delayed or Nonunions with Cavitary Bone Loss

Objective  This study reports on the clinical outcomes of double screw fixation with autologous cancellous bone grafting and early active range of motion for delayed and nonunited scaphoid waist fractures with cavitary segmental bone loss. Patients and Methods  Twenty-one consecutive patients underwent fixation using two 2.2 mm antegrade headless compression screws with autologous distal radius cancellous bone graft. Postoperatively, patients were allowed early active motion with a resting splint until union was achieved. Patients were reviewed radiologically and clinically to assess for fracture union, complications, residual pain, wrist function, and return to work and recreational activities. Results  All but one patient was male, and the mean age was 23 years (range, 15-38 years). The average time from initial injury was 16 months (range, 3-144 months). Nineteen of 21 (90.5%) patients achieved union at a mean of 2.8 months (range, 1.4-9.2 months). Of the patients who failed, one underwent revision surgery with vascularized bone grafting at 10.6 months. The other patient refused further intervention as he was asymptomatic. Conclusion  Double-screw fixation with bone grafting and early active range of motion is a safe and effective technique for management of delayed and nonunited unstable scaphoid fractures with cavitary bone loss. This potentially allows for earlier return to function, without compromise to union rates. Level of Evidence  This is a Level IV, retrospective case series study.

Early mobilization vs delayed mobilisation following the use of a volar locking plate with non-vascularized bone graft in scaphoid non-union. A multicentred randomised controlled-trial

Purpose

This randomized clinical trial investigated the potential for early mobilization of the wrist following open reduction and internal fixation (ORIF) with a scaphoid specific volar locking plate and non-vascularized bone graft for scaphoid non-union.

Methods

16 patients with scaphoid non-union underwent internal fixation with a scaphoid-specific volar locking plate and iliac crest bone graft and were randomized to one of two treatment arms (A) The control were immobilized in a below elbow cast for 6 weeks (n = 9) and (B) The experimental arm were mobilized early with a removable wrist splint (n = 7). Outcomes were measured preoperatively, and at 3 months post operatively. These included the primary outcome of union, and secondary outcomes of grip strength and patient reported outcomes of disabilities of arm shoulder and hand (DASH) and patient reported wrist evaluation (PRWE). Discrete variables were analyzed using the chi squared test while continuous variables used the students t-test.

Results

The experimental (early mobilization) group developed metalware complications resulting in the early termination of the study. No significant difference in the demographic characteristics of age, gender, time to surgery, smoking status and handedness was found between groups. A significant difference was found in BMI, with significantly higher proportion of obese patients (p = 0.05) in the experimental group. There was no significant difference in the primary outcome measure of the rate of union between groups. The secondary outcomes of grip strength, Dash and PRWE also showed no significant difference between the immobilized and mobilized groups.

Conclusion

We recommend immobilization following scaphoid non-union ORIF using a volar locking plate due to high complication rates in our cohort with early mobilization.Type of study/level of evidence: Therapeutic 2.Trial registration.Australian New Zealand Clinical Trials Registry (ACTRN12614001050640). Date of registration, 02/10/2014.

Measurement of Scaphoid Bone Microarchitecture: A Computed Tomography Imaging Study and Implications for Screw Placement

PURPOSE

High bone density and quality is associated with improved screw fixation in fracture fixation. The objective of this study was to assess bone density and quality in the proximal and distal scaphoid to determine optimum sites for placement of 2 screws in scaphoid fracture fixation.

METHODS

Twenty-nine cadaveric human scaphoid specimens were harvested and scanned using micro-computed tomography. Bone density (bone volume fraction) and bone quality (relative bone surface area, trabecular number, and trabecular thickness) were evaluated in 4 quadrants within each of the proximal and distal scaphoid.

RESULTS

The proximal radial quadrant of the scaphoid had significantly greater bone volume than the distal ulnar (mean difference, 33.2%) and distal volar quadrants (mean difference, 32.3%). There was a significantly greater trabecular number in the proximal radial quadrant than in the distal ulnar (mean difference, 16.7%) and in the distal volar quadrants (mean difference, 15.9%) and between the proximal ulnar and the distal ulnar quadrants (mean difference, 12%). There was a significantly greater bone surface area in the proximal radial and distal radial quadrants than in the distal ulnar and distal volar quadrants. There were no significant differences in trabecular thickness between the 8 analyzed quadrants CONCLUSIONS: Although there are differences in bone volume, trabecular number, and bone surface area between the proximal pole of the scaphoid and that of the distal pole, there were no significant differences in the bone quality (trabecular thickness, trabecular number, and relative bone surface area) and density (bone volume fraction) between the 4 quadrants of the proximal or distal pole of the cadaveric scaphoids studied.

CLINICAL RELEVANCE

Insertion of 2 headless compression screws can be determined by ease of surgical access and ease of screw positioning and not by differences in bone quality or density of the proximal or distal scaphoid.

Pull-out forces of headless compression screws in variations of synthetic bone models imitating different types of scaphoid fractures in good bone quality

Screw osteosynthesis using headless compression screws has become the accepted gold standard for the surgical treatment of scaphoid fractures. Optimal screw specifications remain controversially discussed. We aimed to investigate the influence of bone model composition on screw stability tests using headless compression screws in different scaphoid fracture models. We conducted pull-out tests using Acutrak2^®mini, HCS^®, HKS^®, HBS^®, Herbert/Whipple^® and Twinfix^® screws. To imitate cortical and cancellous bone, two-layer polyurethane (PU) models with two distinct densities were produced. The cylinders were cut at different positions to replicate fracture localisations at increasing distances. The maximum pull-out force required to achieve up to 1 mm of pull-out distance (N_{to 1 mm}) was measured. Acutrak2^®mini and HCS^® followed by Twinfix^® showed the greatest average pull-out forces. N_{to 1 mm} was, on average, greater in the cortico-cancellous model than in the cancellous cylinder with the Acutrak2^®mini and the Herbert/Whipple^® screws, while it was the least with the HBS^® and the Twinfix^® screws; there were also differences between the HCS^® and HKS^®. There were no differences between the different fracture simulations in the synthesis strength using either the HKS^® or HBS^®. The pull-out forces of the HCS^® and Twinfix^® remained high also in simulations with the smaller screw base fragments. Varying imitations of cancellous and cortico-cancellous bone and fracture localisation reveal important information about the ex vivo strength of screw syntheses. The grip of the cortical structure should be used with the screws that fit more firmly in cortico-cancellous bone.

Rotational Stability of Scaphoid Waist Nonunion Bone Graft and Fixation Techniques

PURPOSE

Rotational instability of scaphoid fracture nonunions can lead to persistent nonunion. We hypothesized that a hybrid Russe technique would provide improved rotational stability compared with an instrumented corticocancellous wedge graft in a cadaver model of scaphoid nonunion.

METHODS

A volar wedge osteotomy was created at the scaphoid waist in 16 scaphoids from matched-pair specimens. A wedge was inset at the osteotomy site or a 4 × 16-mm strut was inserted in the scaphoid and a screw was placed along the central axis (model 1). The construct was cyclically loaded in torsion until failure. The screw was removed and the proximal and distal poles were debrided. A matching wedge and packed cancellous bone graft or an 8 × 20-mm strut was shaped and fit inside the proximal and distal pole (model 2). A screw was placed and testing was repeated.

RESULTS

In the first model, there was no significant difference in cycles to failure, target torque, or maximal torque between the strut graft and the wedge graft. Cycles to failure positively correlated with estimated bone density for the wedge graft, but not for the strut graft. In the second model, the strut graft had significantly higher cycles to failure, greater target torque, and higher maximal torque compared with the wedge graft. The number of cycles to failure was not correlated with estimated bone density for the wedge or the strut grafts.

CONCLUSIONS

The hybrid Russe technique of inlay corticocancellous strut and screw fixation provides improved rotational stability compared with a wedge graft with screw fixation for a cadaver model of scaphoid waist nonunion with cystic change.

CLINICAL RELEVANCE

The hybrid Russe technique may provide better rotational stability for scaphoid waist nonunions when the proximal or distal scaphoid pole is compromised, such as when there is extensive cystic change, when considerable debridement is necessary, or with revision nonunion surgery.

Single versus double screw fixation for the treatment of scaphoid waist fractures: Finite element analysis and preliminary clinical results in scaphoid nonunion

Objectives

This study aims to compare the single versus double screw fixation of scaphoid waist fractures using finite element analysis, and to present the preliminary clinical results of double screw fixation in a consecutive series of patients with scaphoid nonunion.

Patients and methods

A transverse scaphoid waist fracture (Herbert type B2) model was fixed with either single or double cannulated compression screws. Displacement and rotation of the fragments were performed using three-dimensional finite element analysis in three different wrist positions. A retrospective review was performed on 13 male patients (mean age 31.6±12.8 years; range, 17 to 64 years) who underwent double screw fixation for an established scaphoid nonunion in our clinic between January 2015 and December 2017. Assessment of union was established with serial plain radiographs in eight patients and with wrist computed tomography in five patients. Clinical evaluation was performed using the Mayo wrist score and visual analog scale (VAS).

Results

In all wrist positions, the displacement of the fracture gap in double screw fixation in all planes (x, y, and z) was less than in single screw fixation. Similarly, rotation of the fracture fragments around the longitudinal axis of the scaphoid was lower in double screw fixation. Complete union was obtained in all patients. The mean time to union was 5±0.75 months (range, 4 to 6 months). The mean VAS was 0.8±0.9 (range, 0 to 3). Mayo wrist score was 91±6.9 (range, 80 to 100) at the final follow-up.

Conclusion

Double-screw fixation technique may be a solution to reduce the rate of scaphoid nonunion in unstable type B2 scaphoid fractures or nonunion.

Two-Screw Fixation of Scaphoid Waist Fractures

Optimal fixation strategy for scaphoid waist fractures remains a contentious topic with options including using a single screw, 2 screws, or a scaphoid plate. Biomechanical studies favor 2-screw fixation with regards to higher load to failure, load to 2-mm displacement, energy absorbed, rotational stability, and stiffness. Furthermore, recent retrospective studies found increased union rate with 2 screws. Although conclusive clinical data are lacking, 2-screw fixation of a scaphoid waist fracture may theoretically allow the patient to start earlier range of motion and strengthening with greater confidence. Our experience with 2-screw fixation has been promising with all acute waist fractures healing and nonunions treated with 2 screws having high union and low reoperation rates.

Volar Scaphoid Plating for Nonunion: A Multicenter Case Series Study

Background  The volar scaphoid plate from Medartis (Medartis AG, Austrasse, Basel, Switzerland) is a variable angle titanium locking plate, preformed for the volar aspect of the scaphoid. It does not have compressive capability, and may act as a bridging device. It may provide an advantage over a compression screw where the pathoanatomy is less favorable to such a device with increased rotational stability. It may act as a buttress plate for correction of humpback deformity for example. It has been used in nonunions and with vascularized grafts. Questions  Our study aims to assess the results of our patients with scaphoid nonunion treated with scaphoid volar plating over a larger number of patients. We aim to identify techniques to increase the success of plating. Methods  Patients from our cohort were retrospectively reviewed. Operations were performed by three hand fellowship trained surgeons and in two centers. Inclusion involved a scaphoid plate procedure for a nonunion of the scaphoid with a minimum of 6 months of follow-up. Exclusions were those who had less than 6 months of follow-up. Data included demographics, patient-rated wrist evaluation (PRWE), a quick disabilities of the arm, shoulder, and hand (qDASH), visual analogue score, and range and grip. Radiology was reviewed. Results  Thirty-two eligible patients were assessed. The mean age was 25 years (range 13-46), 2 were female and 15 were smokers. Mean follow-up postsurgery was 18 months. Twenty-nine of 32 patients united (90.6%) on computed tomography scan. Clinical assessment was performed in the 25 patients. The mean qDASH score was 12.5 (range 0-42) and mean PRWE was 11 (range 0-54). The mean arc of motion was 115 degrees. The mean grip strength was 39 kg compared with 41 kg on the nonoperated side. Conclusion  We postulate that the plate acts like an internal bridging device, acting over a small distance, and inherent stability of the construct with structural graft and accurate reduction prior to plating is advantageous. Potential problems include plate impingement on the volar lip of the radius, particularly when trying to plate more proximal fractures. Ideally, it is utilized for mid to distal waist fractures.

Comparative outcome analysis of internal screw fixation and Kirschner wire fixation in the treatment of scaphoid nonunion

In cases with difficult scaphoid screw placement due to small, fragile bone fragments, or transplants and insufficient space, the internal Kirschner wire fixation is a fallback option; however, controversy remains regarding its stability, safety, and outcome. Between 2001 and 2011, 95 patients were treated in our center (n = 80 with cannulated compression screws and n = 15 with Kirschner wires), and retrospectively analyzed. The outcome measurements included the analysis of patient data, union rate and analysis of functional measures, and quality of life. Bony reconstructions were performed with Vascularized Bone Grafts (VBG) based on the 1,2-Intercompartmental Supraretinacular Artery (ICSRA) , Medial Femoral Condyle (MFC)-VBG, cancellous bone, and iliac crest grafts. Bony healing and functional outcome showed no significant differences between Kirschner wire fixation and cannulated compression screws, although significantly more 1,2-ICSRA-VBG were treated with Kirschner wires. Although predominantly used as an intraoperative fallback option, our data demonstrate that Kirschner wire internal fixation can be safe and reliable, with comparable bony union rates and excellent functional outcomes.

Modified Matti-Russe technique using a "butterfly bone graft" for treatment of scaphoid non-union

INTRODUCTION

Autologous bone grafts are used to treat scaphoid non-union with shortening and humpback deformity. The superiority of internally fixed bone graft to embedded bone graft has not been clearly proven.

METHODS

Retrospectively analyzed 42 cases of scaphoid waist non-union treated using the "butterfly bone graft" (modified Matti-Russe technique).

RESULTS

Complete healing was reached by all patients, with an average time of 4.4 (SD ± 0.7) months. Mayo Wrist Score improved from and QuickDASH score significantly improved in all patients after treatment.

CONCLUSIONS

Butterfly bone graft is effective and reliable in treating scaphoid non-union with shortening and humpback deformity.

Factors Associated with Scaphoid Nonunion following Early Open Reduction and Internal Fixation

Background  Nonunion after open reduction and internal fixation (ORIF) of scaphoid fractures is reported in 5 to 30% of cases; however, predictors of nonunion are not clearly defined. Objective  The purpose of this study is to determine fracture characteristics and surgical factors which may influence progression to nonunion after scaphoid fracture ORIF. Patients and Methods  We performed a retrospective case-control study of scaphoid fractures treated by early ORIF between 2003 and 2017. Inclusion criteria were surgical fixation within 6 months from date of injury and postoperative CT with minimum clinical follow-up of 6 months to evaluate healing. Forty-eight patients were included in this study. Nonunion cases were matched by age, sex, and fracture location to patients who progressed to fracture union in the 1:2 ratio. Results  This series of 48 patients matched 16 nonunion cases with 32 cases that progressed to union. Fracture location was proximal pole in 15% (7/48) and waist in 85% (41/48). Multivariate regression demonstrated that shorter length of time from injury to initial ORIF and smaller percent of proximal fracture fragment volume were significantly associated with scaphoid nonunion after ORIF (63 vs. 27 days and 34 vs. 40%, respectively). Receiver operating curve analysis revealed that fracture volume below 38% and time from injury to surgery greater than 31 days were associated with nonunion. Conclusion  Increased likelihood for nonunion was found when the fracture was treated greater than 31 days from injury and when fracture volume was less than 38% of the entire scaphoid. Level of Evidence  This is a Level III, therapeutic study.

Managing the Athlete with a Scaphoid Fracture

Most minimally displaced scaphoid fractures and all displaced scaphoid fractures in elite athletes are treated with early fixation to maximally expedite the return to full function. Computed tomographic (CT) scans are recommended in all scaphoid fractures to facilitate a complete understanding of fracture anatomy and to allow for optimal screw placement. Screw placement is important to maximize healing capacity of the fracture and allow for return to sport. Postoperative CT scans can be helpful to evaluate the extent of healing and may allow patients to return to play sooner.

Practicability of a locking plate for difficult pathologies of the scaphoid

INTRODUCTION

Headless compressions screws are the most implanted devices for scaphoid fractures and nonunions. For cases when screw osteosynthesis is not possible, a special locking plate for scaphoid reconstruction has been developed. The purpose of this study was to evaluate the safety and practicability of this device for difficult scaphoid pathologies.

MATERIALS AND METHODS

Between March 2010 and December 2014, 20 patients (age range 16-59 years) were treated with scaphoid locking plate osteosynthesis. In 17 cases it was due to scaphoid nonunion or delayed union and in three cases to treat a complex multi-fragmentary fracture of the scaphoid. Most of the initial fractures were located either in the proximal third (n = 9) or the middle third (n = 8) of the scaphoid.

RESULTS

Mean follow-up was 14.6 ± 8.9 months (range 2-30 months). All three scaphoid fractures (100%) showed bony healing in the CT scan after 2.7 ± 0.6 months. 15 of 17 (88.2%) patients with scaphoid nonunion demonstrated bony healing in the latest CT scan at an average of 6.2 ± 8.1 months (range 2-11 months) after scaphoid reconstruction. Range of motion (extension/flexion) was 104° ± 18.4° (range 80°-150°) and about one third less than the unaffected side. The average grip strength averaged 38.2 kg on the operated side and 44.1 kg on the unaffected side after surgery. 13 plates (65%) had to be removed due to impaction of the plate or protrusion of the screws.

CONCLUSIONS

This new locking device for scaphoid reconstruction seems to be a safe, useful and reliable tool in the treatment of difficult nonunions or multi-fragmentary scaphoid fractures. The practicability is convincing and satisfying fusion rates can be accomplished. However, most patients require hardware removal. We recommend using this plate as a rescue option when a stable osteosynthesis is necessary for the healing process and screw fixation has already failed or is not possible.

Treatment of scaphoid waist nonunion by one, two headless compression screws or plate with or without additional extracorporeal shockwave therapy

INTRODUCTION

Scaphoid nonunion remains challenging for hand surgeons. Several treatment options are available such as: non-vascularized or vascularized bone grafting, with or without additional stabilization. In the last few decades, extracorporeal shockwave therapy (ESWT) has become an established procedure for treating delayed and nonunions. Purpose of this retrospective follow-up study was (a) to investigate union rate and clinical outcome of the different implants [either one/two headless compression screws (HCS) or a plate] and (b) union rate and clinical outcome using only surgery, or a combination of surgery and ESWT.

MATERIALS AND METHODS

The study included 42 patients with scaphoid nonunions of the waist with a mean follow-up of 52 months. All patients received a non-vascularized bone graft from the iliac crest and stabilization was achieved by using one, two HCS or a plate. ESWT was performed with 3000 impulses, energy flux density per pulse 0.41 mJ/mm² within 2 weeks after surgery. Clinical assessment included range of motion (ROM), pain according to the Visual Analog Scale (VAS), grip strength, Disability of the Arm Shoulder and Hand Score, Patient-Rated Wrist Evaluation Score, Michigan Hand Outcomes Questionnaire and modified Green O'Brien (Mayo) Wrist Score. In addition, each patient had a CT scan of the wrist.

RESULTS

A total of 33/42 (79%) patients showed union at the follow-up investigation. Patients treated with additional ESWT showed bony healing in 21/26 (81%) and without ESWT in 12/16 (75%). Patients that were stabilized using one HCS showed bony healing in 6/10 (60%), with two HCS 10/12 (83%) and by plate 17/20 (85%). The ESWT group had a significantly lower pain score according to the VAS and better modified Green O'Brien (Mayo) Score. No differences could be found in respect of ROM, grip strength, functional outcome score depending of which stabilization method was used.

CONCLUSIONS

Stabilization of scaphoid waist nonunions with two HCS or plate showed higher union rates than a stabilization using only one HCS. In addition, ESWT combined with a nonvascularized bone graft from the iliac crest seems a suitable option for treating scaphoid nonunions.

Factors associated with union time of acute middle-third scaphoid fractures: an observational study

Background

The aim of this study was to investigate the union time of acute middle-third scaphoid fractures following treatments and to analyze the effect of different factors on late union.

Patients and methods

We retrospectively reviewed patients with acute middle-third scaphoid fracture at our institution between January 2013 and December 2017. Patient demographics, fracture characteristics, and treatment strategy, such as age, gender, body mass index, habit of smoking, sides of injury, dominant hand, ulnar variance, multiple fractures, and treatment methods, were investigated. Univariate and multivariate analyses were used to identify possible predictive factors.

Results

A total of 132 patients with scaphoid fracture were included in our study. Operation was performed in 67 patients (50.8%), and conservative treatment was performed in the other 65 patients (49.2%). The union time was 7.2±0.5 weeks. In the multivariate logistic regression analysis, late diagnosis (odds ratio, 1.247; 95% CI, 1.022–1.521) and conservative treatment method (odds ratio, 1.615; 95% CI, 1.031–2.528) were identified as 2 independent predictors of late union in scaphoid fractures patients. Other parameters were not demonstrated to be predictive factors.

Conclusion

Late diagnosis and conservative treatment were two factors associated with late union. Long time of follow-up is necessary for patient with these factors.