A Systematic Review and Meta-Analysis Examining the Differences Between Nonsurgical Management and Percutaneous Fixation of Minimally and Nondisplaced Scaphoid Fractures

Minimally Invasive Percutaneous Screw Guided by 3-Dimensional-Printed Guide for the Treatment of Scaphoid Fractures

PURPOSE

This study aimed to explore the feasibility and efficacy of percutaneous fixation of minimally displaced scaphoid waist fractures using a 3-dimensional-printed guide in 10 cases.

METHODS

Fractures were examined using preoperative computed tomography. The skin interface and bone models were reconstructed using computed tomography data. Guidewire insertion was assisted by a guide. Computed tomography was performed 4-6 weeks after surgery until healing of the fracture was confirmed. The mean follow-up period was 7 months (range, 6-9 months). The fracture healing time, grip strength, flexion-extension arc, patient-rated wrist evaluation, and Mayo wrist score were recorded.

RESULTS

A total of 6 hands were in the dominant limb. The mean operation time was 41 minutes (range, 32-70 minutes). Three (30%) scaphoids healed at 6 weeks after surgery, 8 (80%) scaphoids healed at 8 weeks after surgery, and 100% scaphoids healed at 12 weeks after surgery. After correcting for hand dominance, the mean grip strength was 84% (range, 71% to 95%) of that of the contralateral side. The flexion-extension arc was 97% (range, 82% to 100%) of that of the contralateral side. The mean Mayo wrist score was 95 (range, 85-100), and pain decreased to minimal levels. All patients returned to their preinjury activities.

CONCLUSIONS

Three-dimensional printing is an effective and feasible technology that can help guide intraoperative processes.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic V.

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.

Postoperative Immobilization of Scaphoid Fractures: A Comprehensive Review of the Literature

The optimal protocol for postoperative immobilization following operative treatment of scaphoid fractures remains controversial. Reports of successful management with brief postoperative immobilization suggest that earlier restoration of function may be achieved by limiting the duration of immobilization. However, the risk of nonunion and its associated complications suggest that a more conservative approach with extended immobilization could optimize fracture healing. This paper presents a thorough review of the relevant literature and summarizes the myriad postoperative immobilization protocols and their reported outcomes. Postoperative immobilization protocols and reported outcomes for displaced, comminuted, and proximal pole fractures are discussed separately. The literature is reviewed following different operative techniques, including open reduction internal fixation and percutaneous screw fixation. Vigilant postoperative care of scaphoid fractures managed surgically is warranted to monitor for signs of nonunion while attempting to regain motion and strength to the injured wrist.

Hand Surgeons Are Tackling Tougher Scaphoids: A Study of ABOS Candidate Data

BACKGROUND

This study will evaluate whether those who have completed a hand fellowship treat a disproportionate number of scaphoid fractures based on recent American Board of Orthopaedic Surgery (ABOS) data. We hypothesize that surgeons who have completed a fellowship in hand surgery will address most surgically treated scaphoid fractures, particularly those with fracture nonunions or requiring graft.

METHODS

We queried the ABOS database for case log information submitted for part II of the ABOS examination. This search included all cases with Current Procedural Terminology codes for procedures related to scaphoid fixation. Demographic information, case volume, type of case, and complication rate were compared for hand fellowship-trained surgeons and those who had completed other fellowships as well as non-fellowship-trained surgeons.

RESULTS

During the study period, 1686 surgeons reported treating 4244 scaphoid fractures. Of these surgeons, 1180 had completed a hand surgery fellowship. Hand fellowship-trained surgeons were shown to have operatively treated more scaphoid fractures both in total volume and on a per-surgeon basis. Hand fellowship-trained surgeons were also found to have performed a significantly higher proportion of difficult cases, which were those listed as being a malunion/nonunion or those incorporating a pedicle graft. There was no difference in the complication rate between the 2 groups.

CONCLUSION

Among those orthopedic surgeons reporting case information for part II of the ABOS certification examination, statistically significant differences exist in case volume and case difficulty among surgeons with different areas of fellowship training. Complication rates increase with patient age and examination year.

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.

Excessive Derotational K-Wire Angulation Decreases Compression by Headless Compression Screw

Background  Scaphoid fracture is the most common carpal bone fracture. Open reduction internal fixation of scaphoid fractures typically undergo stabilization by a single headless compression screw (HCS). During screw insertion, a derotational Kirschner wire (K-wire) is often placed for rotational control of the near and far fragment. Questions/Purposes  The aim of this study was to determine if there is an angle of derotational K-wire placement in relation to the axis of a HCS that compromises the amount of compression generated at a fracture site by the HCS. We hypothesize that increased off-axis angle will lead to decreased compression across the fracture site. Methods  A Cellular Block 20 rigid polyurethane foam (Sawbones, Vashon, WA) scaphoid model was created to eliminate variability in bone mineral density in cadaveric bone. MiniAcutrak HCS screws (Acumed, Hillsboro, OR) were used for testing. Three conditions were tested: (1) HCS with derotational wire inserted parallel to the HCS (zero degrees off-axis); (2) HCS with derotational wire inserted 10 degrees off-axis; and (3) HCS with derotational wire inserted 20 degrees off-axis. Results  A statistically significant difference in the mean compression of the control group (56.9 N) was found between the mean compression with the derotational K-wire placed 20 degrees off-axis (15.2 N) ( p  = 0.001). Conclusions  Compression at the fracture site could be impeded by placing an excessively angulated off-axis derotation wire prior to insertion of the HCS. Clinical Relevance  Our study adds a new detail to the optimal technique of HCS placement in scaphoid fractures to improve compression and fracture union.

The Conservative Treatment of Some Hand and Carpal Fractures

In recent decades, there has been a trend toward increased use of operative treatment of hand fractures. However, internal stabilization with wires or open reduction and internal fixation of the phalanges and the metacarpals carries a risk of surgical complications that can be avoided by using appropriate conservative treatment. In this article, some hand fractures that can be managed safely without surgery are discussed. In conclusion, when facing a fracture in the hand, the first consideration is whether the fracture can be treated nonoperatively and not which operative treatment is most appropriate. This applies to both displaced and undisplaced fractures.

Cross-Sectional Areas and Volumes Occupied by Implants in Simulated Scaphoid Fractures

PURPOSE

This study determined the volume of bone replaced by an implant at the proximal and distal poles of simulated scaphoid fractures. We also measured the cross-sectional area of the implant relative to the cross-sectional area of the scaphoid at 2 different simulated fracture locations.

METHODS

Microcomputed tomograhy scans of 7 cadaveric scaphoids were used to create 3-dimensional models in which transverse proximal pole and midwaist fractures were simulated. The volume occupied by 5 commonly used implants and the cross-sectional area occupied at the surface of the fractures was measured using a computer modeling software.

RESULTS

For simulated proximal pole fractures, the implants replaced 1.5%-7.4% of the fracture cross-sectional area and 1.2%-6.4% of the proximal fragment bone volume. For midwaist fractures, the implants replaced 1.5%-6.8% of the fracture cross-sectional area and 1.8%-4.6% of the proximal pole volume. Although the different implant designs replaced different areas and volumes, all these differences were small and below 4%.

CONCLUSIONS

This study provides data that relate to one aspect of fracture healing, specifically, the surface area occupied by 5 different implants in proximal and midwaist scaphoid fractures as well as the volume of bone replaced by the implant.

CLINICAL RELEVANCE

As opposed to the impression provided by 2-dimensional planar imaging, when studied using a 3-dimensional model, the volume and surface area replaced by an implant represent a minimal percentage of scaphoid bone, suggesting a negligible clinical effect.

Comparison of Minimally Invasive Operative Treatment with Conservative Treatment for Acute, Minimally Displaced Scaphoid Fractures at 12 Months' Follow-up

Background  Minimally displaced scaphoid fractures can be challenging to diagnose and treat. Cannulated scaphoid screws have made percutaneous stabilization highly effective. Questions  Would minimally invasive operative treatment of minimally displaced scaphoid fractures yield faster return to work when compared with patients treated conservatively? How do functional and patient satisfaction scores compare between the two groups at 12-months follow-up? Patients and Methods  Records from 18 patients (mean age 28.6 years) treated surgically were retrospectively reviewed and compared with a group of 10 patients (mean age 33.3 years, p  = 0.74) treated nonoperatively. Inclusion criteria were a minimum follow-up period of 12 months and radiographic union. Time to return to work was compared between groups. At 12 months' follow-up, wrist range of motion (ROM) and grip strength were compared, as well as pain, satisfaction, and overall wrist function were evaluated by the visual analogue scale (VAS) and the Mayo modified wrist score (MMWS). Results  The mean time to return to work for the operated group was 39.75 days, while for the nonoperated group it was 88.14 days ( p  = 0.002). At the 12 months' follow-up, mean ROM, grip strength, and VAS score did not differ between groups. The mean MMWS was 98.75 for the operated group and 87.5 for the nonoperated group, indicating a better result in patients treated operatively ( p  = 0.03). In addition, two failures of instrumentation were recorded, a seldom seen complication. Conclusion  Percutaneous fixation of minimally displaced scaphoid fractures allows faster return to work and leaves patients more satisfied with their wrist function compared with plaster immobilization at 12 months' follow-up. Level of evidence  This is a Level III, retrospective, case-control study.

3D computational anatomy of the scaphoid and its waist for use in fracture treatment

BACKGROUND

A detailed understanding of scaphoid anatomy helps anatomic fracture reduction, and optimal screw position. Therefore, we analysed (1) the size and shape variations of the cartilage and osseous surface, (2) the distribution of volumetric bone mineral density (vBMD) and (3) if the vBMD values differ between a peripheral and a central screw pathway?

METHODS

Forty-three fresh frozen hand specimens (17 females, 26 males) were analysed with high-resolution peripheral quantitative computed tomography (HR-pQCT) and dissected to compute a 3D-statistical osseous and cartilage surface model and a 3D-averaged vBMD model of the scaphoid. 3D patterns were analysed using principal component analysis (PCA). vBMD was analysed via averaging HR-pQCT grey values and virtual bone probing along a central and peripheral pathway.

RESULTS

(1) PCA displayed most notable variation in length ranging from 1.7 cm (- 2SD) to 2.6 cm (mean) and 3.7 cm (+ 2SD) associated with differences of the width and configuration of the dorsal surface (curved and narrow (4 mm) to a wider width (9 mm)). (2) High vBMD was located in the peripheral zone. Lowest vBMD was observed in the centre and waist. (3) Virtual probing along a peripheral pathway near to the cartilage surfaces for the capitate and lunate allowed the center region to be bypassed, resulting in increased vBMD compared to a central pathway.

CONCLUSION

High anatomical variations regarding the osseous and cartilage surfaces were associated with three distinct concentrically arranged zones with notable different vBMD. The complex scaphoid anatomy with its waist might alter the strategy of fracture fixation, education and research.

Factors Associated With Surgical Treatment of Nondisplaced or Minimally Displaced Scaphoid Waist Fractures

PURPOSE

To determine whether there are identifiable factors associated with the surgical treatment of nondisplaced or minimally displaced scaphoid waist fractures.

METHODS

We identified 50 patients who underwent nonsurgical treatment and 67 patients who underwent surgical treatment of nondisplaced or minimally displaced scaphoid waist fractures at 2 tertiary care referral centers in a single metropolitan area in the United States between January 2010 and March 2019. Bivariate analysis was used to screen for factors associated with surgical treatment. Multivariable stepwise logistic regression was used to determine factors associated with surgical treatment of a nondisplaced or minimally displaced scaphoid fracture.

RESULTS

Multivariable logistic regression analysis showed that male sex (odds ratio = 2.80; 95% confidence interval, 1.20-6.52) and employed status (odds ratio = 3.12, 95% confidence interval, 1.24-7.85) were associated with surgical treatment of nondisplaced or minimally displaced scaphoid waist fractures.

CONCLUSIONS

Male and employed patients have increased odds of undergoing scaphoid surgery for nondisplaced or minimally displaced waist fractures compared with female and unemployed patients. These differences may represent patient preference, surgeon counseling, or a combination. Further study is needed to understand the etiology of this sex difference.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Percutaneous fixation of acute scaphoid waist fractures: Long-term patient-reported functional outcomes and satisfaction at a mean of 11 years following surgery

The aim of this study was to report the long-term functional outcomes and complication rates following early percutaneous fixation of acute fractures of the scaphoid. A trauma database was searched to identify all skeletally-mature patients with an undisplaced or minimally-displaced scaphoid waist fracture managed with early percutaneous retrograde screw fixation over a thirteen-year period from 1997-2010. Medical records were retrospectively reviewed, and complications documented. Long-term follow-up was by a questionnaire-based review. The Patient-Rated Wrist Evaluation (PRWE) was the primary outcome measure. Secondary outcomes included the Quick version of the Disability of the Arm, Shoulder and Hand score (QuickDASH), the EuroQol 5-dimensions score (EQ-5D-5L), and complications. During the study period 114 patients underwent this procedure. The mean age was 28 years (range 17-62) and 97 patients (85%) were male. The median time from injury to surgery was nine days (range 1-27). Twelve patients (11%) reported a complication, all of whom required repeat surgical intervention (six revision ORIF for non-union, five elective removal of hardware, one early revision fixation due to screw impingement). Long-term outcome data was available for 77 patients (68%) at mean follow-up of 11.4 years (range 6.4-19.8). The median PRWE was 0 (IQR 0-7.5), median QuickDASH 0 (IQR 0-4.5) and median EQ-5D-5L 1.0 (IQR 0.837-1.0). There were 97% (n = 74) patients satisfied with their outcome. Early percutaneous fixation of acute non-displaced or minimally displaced scaphoid fractures results in good long-term patient reported outcomes and health-related quality of life. Although comparable with previous studies, the overall surgical reintervention rate is notable and can result in inferior outcomes. LEVEL OF EVIDENCE: Therapeutic level III (Retrospective Cohort Study).

Mid-term follow-up of surgically treated and healed scaphoid fractures

The aim of this study was to evaluate the mid-term results of surgically treated scaphoid fractures since we were concerned that good results might deteriorate over time due to osteoarthritis or functional impairment. Thirty-three out of 121 surgically treated patients (isolated scaphoid fractures n = 23; scaphoid fractures with concomitant injuries n = 10) were evaluated retrospectively (47-138 months). Five patients (4%) had a non-union after internal fixation and were excluded because of additional treatment. The remaining 83 patients were not available for a follow-up examination. Patients with an isolated scaphoid fracture had a mean extension-flexion of 68°-0°-64°, a radial-ulnar deviation of 27°-0°-41° and a grip strength of 39 kg (corresponding to 87-98% of the uninjured contralateral wrist), while patients with concomitant injuries had a mean extension-flexion of 60°-0°-44°, radial-ulnar deviation of 22°-0°-38° and a grip strength of 42 kg (corresponding to 73-98% of the uninjured contralateral wrist). The Michigan Hand Questionnaire score was 85 and 75 and the Patient-Rated Wrist Evaluation score was 8 and 21, respectively. Fifteen patients had radiological signs of radiocarpal osteoarthritis with a significantly higher occurrence in those who had concomitant injuries compared to those with isolated scaphoid fractures (p < 0.01). There was no significant group difference in scaphotrapeziotrapezoid (STT) osteoarthritis (p = 0.968). One STT osteoarthritis case occurred after plate fixation, one after antegrade screw fixation and 10 after retrograde screw fixation. Surgical treatment of an acute isolated scaphoid fracture has excellent clinical, functional, and radiologic mid-term results, while scaphoid fractures with concomitant wrist injuries have slightly inferior results.

A Retrospective Review of Differences in Complication Rates between Dorsal Percutaneous and Mini-Open Surgical Fixation of Scaphoid Fractures

Objective  We retrospectively reviewed the complications of 80 cases of scaphoid screw fixation in acute fractures and early nonunions comparing dorsal percutaneous and mini-open approaches. Methods  We performed a chart review of all patients who underwent surgical fixation of a scaphoid fracture or a nascent nonunion using a dorsal percutaneous or dorsal mini-open technique by a single surgeon. We collected data on patient demographics, including age and smoking status, time to surgery, fracture type, union, and the major and minor complications that occurred in each group. Fisher's exact tests were used to compare the complication rates between the groups. Results  We identified 80 patients who underwent surgical fixation. Of these, 44 underwent percutaneous fixation and 36 underwent mini-open fixation. All fractures went on to heal. There was a total of five complications identified. There were no major complications in the percutaneous group, but one major complication in the mini-open group (a delayed union that eventually healed at 6 months). There were two minor complications in each group. There was no statistically significant difference in total, major, or minor complication rates between the groups. Conclusions  This study suggests that a dorsal percutaneous surgical technique for scaphoid fracture repair does not affect the complication rate despite prior literature to the contrary. Both techniques analyzed produce excellent rates of union with very low complication rates. Surgeon-specific technique rather than operative approach or exposure may be responsible for previously reported complication rates in the fixation of scaphoid fractures. Level of Evidence  This is a level III, therapeutic study.

Surgical fixation compared with cast immobilisation for adults with a bicortical fracture of the scaphoid waist: the SWIFFT RCT

BACKGROUND

Scaphoid fractures account for 90% of carpal fractures and occur predominantly in young men. Immediate surgical fixation of this fracture has increased.

OBJECTIVE

To compare the clinical effectiveness and cost-effectiveness of surgical fixation with cast treatment and early fixation in adults with scaphoid waist fractures that fail to unite.

DESIGN

Multicentre, pragmatic, open-label, parallel two-arm randomised controlled trial with an economic evaluation and a nested qualitative study.

SETTING

Orthopaedic departments of 31 hospitals in England and Wales recruited from July 2013, with final follow-up in September 2017.

PARTICIPANTS

Adults (aged ≥ 16 years) presenting within 2 weeks of injury with a clear, bicortical fracture of the scaphoid waist on plain radiographs.

INTERVENTIONS

Early surgical fixation using Conformité Européenne-marked headless compression screws. Below-elbow cast immobilisation for 6-10 weeks and urgent fixation of confirmed non-union.

MAIN OUTCOME MEASURES

The primary outcome and end point was the Patient-Rated Wrist Evaluation total score at 52 weeks, with a clinically relevant difference of 6 points. Secondary outcomes included Patient-Rated Wrist Evaluation pain and function subscales, Short Form questionnaire 12-items, bone union, range of movement, grip strength, complications and return to work.

RESULTS

The mean age of 439 participants was 33 years; 363 participants were male (83%) and 269 participants had an undisplaced fracture (61%). The primary analysis was on 408 participants with valid Patient-Rated Wrist Evaluation outcome data for at least one post-randomisation time point (surgery, n = 203 of 219; cast, n = 205 of 220). There was no clinically relevant difference in the Patient-Rated Wrist Evaluation total score at 52 weeks: the mean score in the cast group was 14.0 (95% confidence interval 11.3 to 16.6) and in the surgery group was 11.9 (95% confidence interval 9.2 to 14.5), with an adjusted mean difference of -2.1 in favour of surgery (95% confidence interval -5.8 to 1.6; p = 0.27). The non-union rate was low (surgery group, n = 1; cast group, n = 4). Eight participants in the surgery group had a total of 11 reoperations and one participant in the cast group required a reoperation for non-union. The base-case economic analysis at 52 weeks found that surgery cost £1295 per patient more (95% confidence interval £1084 to £1504) than cast treatment. The base-case analysis of a lifetime-extrapolated model confirmed that the cast treatment pathway was more cost-effective. The nested qualitative study identified patients' desire to have a 'sense of recovering', which surgeons should address at the outset.

LIMITATION

There were 17 participants who had initial cast treatment and surgery for confirmed non-union, which in 14 cases was within 6 months from randomisation and in three cases was after 6 months. Three of the four participants in the cast group who had a non-union at 52 weeks were not offered surgery.

CONCLUSIONS

Adult patients with an undisplaced or minimally displaced scaphoid waist fracture should have cast immobilisation and suspected non-unions immediately confirmed and urgently fixed. Patients should be followed up at 5 years to investigate the effect of partial union, degenerative arthritis, malunion and screw problems on their quality of life.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN67901257.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 52. See the NIHR Journals Library website for further project information.

A Mini-Open, Dorsal Approach for Scaphoid Fracture Fixation With a Ligament Sparing Arthrotomy

There are several surgical approaches that are currently used to address nondisplaced scaphoid waist fractures, including percutaneous fixation, limited exposure fixation, and traditional open techniques through a volar or dorsal approach. Although percutaneous fixation has some theoretical advantages, it is much more difficult to achieve an accurate starting point for a headless compression screw. The purpose of this paper is to describe a simple, dorsal, mini-open approach to the scaphoid that minimizes incision size, extensor tendon dissection, capsular trauma, and vascular disruption, while still allowing for direct visualization of the proximal pole and optimal exposure for accurate screw placement. As a case report, we retrospectively evaluated 80 consecutive patients with closed scaphoid fractures. There were 2 groups, with 44 patients (age: 24±10 y) receiving a percutaneous dorsal approach and 36 patients (age: 30±16 y) treated with a mini-open approach. All scaphoid fractures were acute or fibrous nonunions (<6 mo from injury, except for one) treated with cannulated headless compression screws. Intraoperative and postoperative complications were measured and evaluated for each group to assess for differences between the percutaneous approach and the mini-open technique. We found no significant difference in complication rate with the mini-open dorsal technique compared with the dorsal percutaneous approach (8.3% vs. 4.5%, respectively). Therefore, we suggest consideration of this mini-open dorsal approach for scaphoid fracture fixation as a useful and safe technique.

The Vascular Anatomy of the Scaphoid: New Discoveries Using Micro-Computed Tomography Imaging

PURPOSE

The purpose of this study was to investigate the intraosseous vascular anatomy of the scaphoid using recent advances in micro-computed tomography (micro-CT) imaging and 3-dimensional reconstruction. We also studied the effect of scaphoid shape and screw position on the intraosseous vascular structure.

METHODS

Thirteen upper extremities were injected with a contrast agent. The scaphoid bones were extracted and scanned using a micro-CT scanner. The vascular impact of screw insertion at various axes through the scaphoid was calculated and compared using the generated 3-dimensional models. The specimens were 3-dimensionally-printed and the morphology was assessed according to bone dimensions. A relationship between the internal vascular patterns and these morphological features was determined.

RESULTS

All specimens received vascular inflow from the dorsal ridge forming a vascular network that supplied an average of 83% of the bone's volume. This network was supplemented in 4 specimens with volar vessels entering at the waist. Another network was identified, created by vessels entering volarly at the tubercle, which supplied the remainder of the scaphoid. One specimen did not receive any vessels at the tubercle. With regards to screw placement, screws placed in the central axis were the least disruptive to the internal vascularity, followed by the antegrade (dorsal) insertion axis. Two morphological bone types were identified: type I or full scaphoids and type II or slender scaphoids. Type I possessed a more robust internal vascular network than type II scaphoids.

CONCLUSIONS

This study identifies 2 distinct types of scaphoid morphology with 1 of them having a less robust blood supply, which may prove to be related to development of nonunion, avascular necrosis, or Preiser disease. Central axis and antegrade (dorsal) screw fixation may be least disruptive to the internal blood supply.

CLINICAL RELEVANCE

Safer fixation of the scaphoid bone may be achieved by knowledge of intraosseous vascular patterns.

Prosthetic Arthroplasty of Proximal Interphalangeal Joints for Treatment of Osteoarthritis and Posttraumatic Arthritis: Systematic Review and Meta-Analysis Comparing the Three Ulnar Digits With the Index Finger

Background: It is common teaching that treatment of index finger alone is a relative contraindication for arthroplasty of the proximal interphalangeal joint (PIPJ). However, limited data exist reporting the digit-specific complication of PIPJ arthroplasty for the treatment of osteoarthritis or posttraumatic arthritis. The purpose of this article is to perform a systematic review and meta-analysis of the literature to assess whether the 3 ulnar digits may bear a similar instability and complication profile. Methods: Systematic searches of the MEDLINE, EMBASE, and Cochrane computerized literature databases were performed for PIPJ arthroplasty specifying by digit. We reviewed both descriptive and quantitative data to: (1) report aggregate instability and instability-related complications after non-index digit PIPJ arthroplasty; and (2) perform statistical testing to assess relative rates by digit and compared with index digits. Results: Computerized search generated 385 original articles. Five studies reporting digit-specific instability-related outcomes of silicone, pyrocarbon, or metal surface arthroplasty on 177 digits were included in the review. Meta-analysis demonstrated a 29% instability rate for long digits (n = 65), 6% for ring digits (n = 53), and 6% for small digits (n = 17), compared with 33% for index digits (n = 42). There was no difference in the overall deformity, instability, and complication rates of long versus index fingers (P = .65). Conclusions: Instability-related deformity and complication rates of long finger PIPJ arthroplasty may not be different from that of the index finger. Treatment of the long finger may be a relative contraindication to PIPJ arthroplasty. Future biomechanical and clinical studies are needed.

Volar Approach to Percutaneous Fixation of Acute Nondisplaced Fractures of the Scaphoid

Scaphoid fractures typically occur in young, healthy males at the peak of their employment and productivity, and left untreated or inadequately treated will ultimately progress to nonunion and a "predictable" pattern of wrist arthritis and carpal collapse. Nonoperative treatment of these fractures requires prolonged cast immobilization, which can lead to wrist stiffness, loss of grip strength, muscle atrophy, and protracted loss of economic productivity. To prevent these devastating sequelae, percutaneous techniques for scaphoid fixation have been described and popularized; however, these techniques are technically demanding as optimal position of the compression screw is required to achieve bony union. The focus of this paper is to describe the indications, contraindications, and a series of reproducible, practical pearls to achieve ideal percutaneous scaphoid compression screw fixation of scaphoid waist and distal pole fractures.

Comparison of volar versus dorsal screw fixation for scaphoid waist fractures: A finite element analysis

PURPOSE

Scaphoid waist fractures may be fixed through volar or dorsal screw fixation. However, there is no consensus on which surgical fixation method should be performed. The purpose of this study was to compare volar versus dorsal screw fixation of scaphoid waist fractures under physiological loading conditions utilizing finite element analysis.

METHODS

A transverse scaphoid waist fracture (Herbert type B2) model was fixed with a headless cannulated compression screw using either a volar or dorsal approach. Displacement and rotation of the fragments and stress analysis on the scaphoid bone and screw were analyzed in the models using 3-D finite element analysis in three different wrist positions; total extension (TE), neutral (N) and total flexion (TF).

RESULTS

Displacement of the fracture gap in volar fixation in all planes (x, y, z) was less than in dorsal fixation in the TF and N positions. Furthermore, rotational stability was stronger in volar fixation in all planes and wrist positions. von Mises stress values were concentrated on the proximal fragment in all wrist positions.

CONCLUSIONS

Although both volar and dorsal fixation techniques can be preferred in Herbert type B2 fractures, results of this finite element analysis suggest that centrally placed volar compression screw fixation may be biomechanically advantageous over dorsal screw fixation.

LEVEL OF EVIDENCE

I.

Surgical versus nonsurgical treatment for scaphoid waist fracture with slight or no displacement: A meta-analysis and systematic review

BACKGROUND

Surgical or nonsurgical treatment for scaphoid waist fracture with slight or no displacement is still controversial. This study compared the efficacy of the 2 methods through meta-analysis to provide a reference for the choice of clinical treatment options.

METHODS

Two individuals independently searched for relevant RCTs and cohort studies from PubMed (1946-February 2018), Embase (1946-February 2018), and Cochrane library (1997-February 2018). After quality assessment and data extraction, Stata 14 software was used for combining the effect size, testing heterogeneity, and studying bias. GRADEpro was used to rate the level of evidence.

RESULTS

Ten RCTs and 4 cohort studies with 765 patients were included. No statistical difference in satisfaction, pain, and Disability of the Arm, Shoulder, and Hand score was found after surgical and nonsurgical treatments. Compared with nonsurgical treatment, surgical treatment shortened the time to union (SMD = -5.01, 95% CI: -7.47 to -2.58, P = .000), decreased the convalescence (SMD = -2.09, 95% CI: -3.08 to -1.11, P = .000), and reduced the incidence of nonunion (RR = 0.47, 95% CI: 0.24-0.90), P = .023). Subgroup analyses showed that the percutaneous fixation treatment can shorten the time to union [SMD = -1.82, 95%CI (-2.22 to -1.42), P = = .000] and the convalescence (SMD = -4.26, 95%CI: -6.16 to -2.35, P = = .054), and open reduction fixation treatment can reduce the incidence of nonunion (RR = 0.20, 95%CI: 0.06-0.69, P = = .01).

CONCLUSION

For scaphoid waist fractures with slight or no displacement, there was no statistical difference in patient satisfaction, pain, and The Disability of the Arm, Shoulder, and Hand scores between surgical treatment and nonsurgical treatment. Closed surgical treatment can shorten the time to union and convalescence, and open reduction can reduce the incidence of nonunion. On the basis of this conclusion, chief physicians can consider which treatment to use according to the patient's clinical situation and their subjective intention.

[Ultrasound-guided percutaneous Herbert screw for the treatment of fresh nondisplaced carpal scaphoid fracture]

Objective

To explore the effectiveness of ultrasound-guided percutaneous Herbert screw for the treatment of fresh nondisplaced carpal scaphoid fracture.

Methods

Between May 2013 and August 2015, 15 patients with fresh nondisplaced carpal scaphoid fractures (Krimmer type A2) were treated with ultrasound-guided Herbert screw fixation. There were 12 males and 3 females with an average age of 33.4 years (range, 18-51 years). The causes of injury included 9 cases of falls, 3 cases of training injuries, and 3 cases of machine injuries. The interval from injury to surgery was 2-15 days (mean, 5 days). No other complication was found. The operation time, intraoperative blood loss, intraoperative fluoroscopy times, and the fracture healing time were recorded. The wrist function was assessed by the modified Mayo wrist score standard.

Results

The operation time was 28-53 minutes (mean, 33.9 minutes); the intraoperative blood loss was 5-30 mL (mean, 10.5 mL); the intraoperative fluoroscopy was 2-6 times (mean, 2.6 times). All 15 patients were followed up 6-18 months (mean, 10.5 months). One patient developed pain and soreness in the skin of the nail entrance, and gradually relieved after fumigation. No complication such as infection occurred. All fractures healed clinically, and the healing time was 8-16 weeks (mean, 11.6 weeks). At last follow-up, the modified Mayo wrist score was 76-99 (mean, 92.5). Among them, 12 cases were excellent, 2 cases were good, and 1 case was fair, and the excellent and good rate was 93.3%.

Conclusion

Ultrasound-guided fixation with Herbert screw is a reliable treatment method for fresh nondisplaced carpal scaphoid fractures with small invasion, less bleeding, and small radiation damage.

Rising incidence of scaphoid fracture surgery in Finland

The aim of the present study was to investigate the incidence of scaphoid fracture surgery by obtaining data from the national discharge register in Finland, a country of 5 million inhabitants, for the period from 1997 to 2014. A total of 1380 patients with scaphoid fracture were treated surgically. Half of the patients were aged under 28 years and 84% were men. The surgical treatment of scaphoid fractures was classified into two groups. There were 640 (46%) primary fracture fixations and 740 (54%) treatments of fracture nonunion. The overall incidence of all scaphoid fixations increased twofold (from 14.8 to 30.1 per 1,000,000 person-years) and threefold in the primary fixation group (from 5.5 to 17.8 per 1,000,000 person-years) during the study period.

LEVEL OF EVIDENCE

III.

Controversies and best practices for acute scaphoid fracture management

Acute scaphoid fractures are common wrist injuries that continue to elicit debate from surgeons regarding the most appropriate diagnostic and management algorithms. This review will examine the current literature and trends, in an attempt to provide the reader with an evidence-based discussion regarding current controversies of interest to clinicians. In addition, an attempt will be made to provide recommendations for the best treatment practices for acute scaphoid fractures.

Stabilization of scaphoid type B2 fractures with one or two headless compression screws

INTRODUCTION

Fractures of the scaphoid account for the most commonly injured carpal bone. Minimally displaced fractures of the waist will heal in 85-90% when using a below elbow cast. However, fractures with displacement have a higher risk for nonunion. Therefore, open reduction and fixation with headless compression screws (HCS) have become the preferred method of treatment. The aim of this study was to compare the radiological and clinical outcome of unstable scaphoid B2 type fractures, stabilized using one or two headless compression screws.

PATIENTS AND METHODS

A total of 47 unstable scaphoid B2 type fractures were included in this retrospective follow-up study. Twelve patients were not accessable and three refused to attend follow-up checks. Therefore, a total of 32 patients were included in this study with a mean follow-up interval of 43 (12-81) months. Twenty-two patients were treated using one HCS and ten with two HCS. Clinical assessment included range of motion (ROM), pain according to the visual analogue 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 Wrist Score. The follow-up study on each patient included a CT-Scan of the wrist which was analyzed for union, osteoarthritis, dorsiflexed intercalated segment instability and humpback deformity.

RESULTS

Radiologically, 29/32 (91%) of the scaphoid B2 type fractures showed union, 10/10 (100%) in the two HCS group and 19/22 (86%) in the one HCS group (p < 0.05). No significant differences could be found in respect to ROM, grip strength, VAS and scores between the groups. Screw removal was necessary in two patients in the two HCS group and one in the one HCS group.

CONCLUSION

The unstable B2 type fractures of the scaphoid, when using two HCS without bone grafting is a safe method, shows a significantly higher union rate and equal clinical outcome compared to stabilization using only one HCS.