Scaphoid nonunions treated with 2 headless compression screws and bone grafting

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.

Bilateral Scaphoid Fractures: A Systematic Literature Review

Bilateral scaphoid fractures are rare lesions, warranting a review to synthesize current knowledge, identify gaps, and suggest research directions. Two authors, adhering to PRISMA guidelines, in January 2024 identified 16 case reports (1976-2023). Data extraction included demographics, injury mechanisms, associated injuries, fracture sites, treatments, and outcomes. Among 121 initial outcomes, 16 articles met the criteria, predominantly affecting young people (93.75% males, mean age 22 years). High-energy traumas (75%) often caused associated wrist injuries (68.75%). Most fractures required surgical intervention (68.75%), primarily headless compression screws. Bilateral scaphoid fractures, which are rare but associated with high-energy traumas, commonly involve wrist injuries. Surgical management is often necessary, yielding better outcomes with fewer complications. Further research is essential to understand the epidemiology, optimal management, and long-term results. Early diagnosis and appropriate treatment are crucial for preventing complications and ensuring favorable patient outcomes.

Traditional Bone Grafting in Scaphoid Nonunion

Management of scaphoid nonunion remains challenging despite modern fixation techniques. Nonvascularized bone graft may be used to achieve union in waist and proximal pole fractures with good success rates. Technical aspects, such as adequate debridement and restoration of scaphoid length, and stable fixation are critical in achieving union and functional wrist usage. Rigid fixation can be achieved with compression screws, K-wires, and plate constructs. The surgeon has a choice of various bone graft options including corticocancellous, cancellous, and strut grafts to promote healing and correct the humpback deformity.

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 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.

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.

Vascularised versus non-vascularised bone graft for scaphoid nonunion: Meta-analysis of randomised controlled trials and comparative studies

Background

Numerous studies have investigated surgical techniques for vascularised bone graft (VBG) for scaphoid nonunion; however, their efficacies remain unclear. Thus, to estimate the union rate of VBG for scaphoid nonunion, we performed a meta-analysis of randomised controlled trials (RCTs) and comparative studies.

Methods

A systematic search was conducted using PubMed, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials. The search formula was as follows: ((scaphoid nonunion) OR (scaphoid pseudarthrosis)) AND (bone graft). Only RCTs were used in the primary analysis, and comparative studies, including RCTs, in the secondary analysis. The primary outcome was nonunion rate. We compared the outcome between VBG and non-vascularised bone graft (NVBG), pedicled VBG and NVBG, and free VBG and NVBG.

Results

This study included a total of 4 RCTs (263 patients) and 12 observational studies (1411 patients). In the meta-analyses of both RCTs only and RCTs and other comparative studies, no significant difference in nonunion rate was found between VBG and NVBG (summary odds ratio [OR], 0.54; 95% confidence interval [CI], 0.19-1.52 and summary OR, 0.71; 95% CI, 0.45-1.12), respectively. The nonunion rates of pedicled VBG, free VBG, and NVBG were 15.0%, 10.2%, and 17.8%, respectively, and no significant difference was found.

Conclusions

Our results indicated that the postoperative union rate in NVBG is similar to that in VBG; thus, NVBG could be the first choice of treatment for scaphoid nonunion.

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.

Single Versus Dual Headless Compression Screw Fixation of Scaphoid Nonunions: A Biomechanical Comparison

BACKGROUND

Management of scaphoid nonunions with bone loss varies substantially. Commonly, internal fixation consists of a single headless compression screw. Recently, some authors have reported on the theoretical benefits of dual-screw fixation. We hypothesized that using 2 headless compression screws would impart improved stiffness over a single-screw construct.

METHODS

Using a cadaveric model, we compared biomechanical characteristics of a single tapered 3.5- to 3.6-mm headless compression screw with 2 tapered 2.5- to 2.8-mm headless compression screws in a scaphoid waist nonunion model. The primary outcome measurement was construct stiffness. Secondary outcome measurements included load at 1 and 2 mm of displacement, load to failure for each specimen, and qualitative assessment of mode of failure.

RESULTS

Stiffness during load to failure was not significantly different between single- and double-screw configurations (P = .8). Load to failure demonstrated no statistically significant difference between single- and double-screw configurations. Using a qualitative assessment, the double-screw construct maintained rotational stability more than the single-screw construct (P = .029).

CONCLUSIONS

Single- and double-screw fixation constructs in a cadaveric scaphoid nonunion model demonstrate similar construct stiffness, load to failure, and load to 1- and 2-mm displacement. Modes of failure may differ between constructs and represent an area for further study. The theoretical benefit of dual-screw fixation should be weighed against the morphologic limitations to placing 2 screws in a scaphoid nonunion.

Scaphoid Nonunion: A Review of Surgical Strategies

The scaphoid is predisposed to nonunion after fracture because of its tenuous blood supply and propensity for delayed diagnosis. Many surgical techniques exist and continue to be developed to treat scaphoid non-unions. However, with variability in patient presentation, differences in nonunion location and type, and multiple bone graft sources and fixation options, selecting a surgical strategy proves a difficult task. The goal of this article is to provide an updated review of surgical strategies used to treat scaphoid nonunions. Particular attention is paid to methods of fixation as well as the ongoing debate over indications for structural and vascularized bone grafting. [Orthopedics. 2022;45(5):e235-e242.].

Plate fixation in challenging traumatic carpal scaphoid lesions

BACKGROUND

Complex fractures of the carpal scaphoid with poles fragmentation, edges comminution, bone loss and non-union of fractures previously treated by screw fixation remain challenging for hand surgeons. The authors present the indications, advantages and results of scaphoid plating, underlining the importance of correct plate positioning well shaped onto the bone.

MATERIALS AND METHODS

The study includes 11 patients presenting acute fracture with distal pole fragmentation, acute fracture with comminution and non-union after prior failure of screw fixation. All patients were treated with volar locked plate fixation, adding a cortical bone graft in cases of non-union.

RESULTS

Bone consolidation was achieved in all cases; excellent outcomes in fracture healing and relevant improvement in symptoms and functions were obtained in non-union group that are consistent with the literature. Only one patient underwent early further surgery (first row carpectomy) with poor results.

CONCLUSION

The treatment of the selected scaphoid lesions with volar locked plate is a surely efficient technique. The plate can be easily adjusted to the shape of the scaphoid and can achieve an adequate correction of bone deformity and high degree of stability both in non-union and fractures.

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.

Clinical and Patient-Reported Outcomes After Hybrid Russe Procedure for Scaphoid Nonunion

Background: Hybrid Russe technique for the treatment of scaphoid nonunion with humpback deformity has been described with a reported 100% union rate. We sought to evaluate the reproducibility of this technique. Methods: We completed a retrospective chart review of patients with a scaphoid waist nonunion and humpback deformity treated with the hybrid Russe technique from 2015 to 2019 with a minimum of 3-month follow-up. Twenty patients with 21 nonunions were included (mean follow-up: 7.0 months). Scapholunate angle was the primary outcome measure. Secondary outcomes included: intrascaphoid angle, radiolunate angle, pain on the visual analog scale (VAS), and Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score. Other variables included: time to computed tomography (CT) union, range of motion, and complications. Descriptive statistics were presented. Pre- and postoperative angles, VAS, and QuickDASH scores were evaluated with Wilcoxon signed rank tests. Results: The mean scapholunate angle improved -17.6° ± 6.4°. The mean intrascaphoid angle improved 28.2° ± 6.3°. The mean radiolunate angle improved 12.8° ± 8.8°. Of the 21 scaphoids, 20 (95%) demonstrated union on a CT scan. One patient was diagnosed with a nonunion. In total, 90% of patients noted symmetric range of motion compared with the contralateral side. The mean VAS pain score improved 6 ± 3 points. The mean QuickDASH score improved 10 ± 8 points. Complications (aside from nonunion) included 1 patient with persistent wrist pain that resolved with removal of hardware. Conclusions: The hybrid Russe technique for the treatment of scaphoid nonunions with humpback deformity demonstrates a 95% union rate. This technique is effective, reproducible, and may serve as an alternative to techniques that include structural grafts from distant sites.

Volar Plating versus Headless Compression Screw Fixation of Scaphoid Nonunions: A Meta-analysis of Outcomes

Background  Headless compression screw fixation with bone grafting has been the mainstay of treatment for scaphoid nonunion for the past several decades. Recently, locked volar plate fixation has gained popularity as a technique for scaphoid fixation, especially for recalcitrant or secondary nonunions. Purpose  The purpose of this meta-analysis was to compare union rates and clinical outcomes between locked volar plate fixation and headless compression screw fixation for the treatment of scaphoid nonunions. Methods  A literature search was performed for studies documenting treatment outcomes for scaphoid nonunions from 2000 to 2020. Inclusion criteria consisted of (1) average age > 18 years, (2) primary study using screw fixation, plate fixation, or both, with discrete data reported for each procedure, and (3) average follow-up of at least 3 months. Exclusion criteria consisted of studies with incomplete or missing data on union rates. Data from each study was weighted, combined within treatment groups, and compared across treatment groups using a generalized linear model or binomial distribution. Results  Following title and full-text review, 23 articles were included for analysis. Preoperatively, patients treated with plate fixation had significantly longer time from injury to surgery and were more likely to have failed prior surgical intervention. There was no significant difference between union rates at 92 and 94% for screw and plate fixation, respectively. However, plate fixation resulted in longer time to union and lower modified Mayo wrist scores. Conclusion  Patients treated with locked volar plate fixation were more likely to be used for recalcitrant or secondary nonunions. There was no statistically significant difference in union rates between screw and plate fixation. The results from this meta-analysis support the select use of locked volar plate fixation for scaphoid nonunion, especially recalcitrant nonunions and those that have failed prior surgical repair.

Evaluation of the mechanical properties and clinical application of nickel-titanium shape memory alloy scaphoid arc nail

To investigate the mechanical and biomechanical properties of nickel-titanium (Ni-Ti) shape memory alloy scaphoid arc nail (NT-SAN) fixator as well as study the surgical method of treating carpal scaphoid fractures and evaluate its clinical efficacy. (1) Static and dynamic bending tests with embedded axial bending fixture were conducted to study the mechanical properties. (2) To evaluate biomechanical strength and fatigue, 32 scaphoid samples were classified into four groups to perform the fixation rigidity test: intramedullary Kirschner fixation (group A), Kirschner straddle nail fixation (group B), screw nail fixation (group C), and NT-SAN fixation (group D). Next, 24 scaphoid waist fracture models were classified to conduct fatigue experiments as follows: Kirschner straddle nail fixation (group E), screw nail fixation (group F), and NT-SAN fixation (group G). (3) The Krimmer score chart was used for clinical evaluations. (1) NT-SAN showed excellent mechanical performance and a long lifespan. (2) NT-SAN was fixated with a strong intensity and an anti-fatigue outcome. (3) Ninety-eight interviewed patients were satisfied with the therapeutic effects of the arc nail (satisfaction rate: 95.92%). The designed strength and hardness of NT-SAN corresponded with the anatomical characteristics of the scaphoid, and the designed mechanical properties met the biomechanical requirements of a scaphoid fracture. The fatigue strength can meet the requirements of bone healing after the scaphoid fracture. Clinical trials on NT-SAN scaphoid fracture treatment have shown that the surgery is simple and the clinical results are satisfactory. The therapeutic level of NT-SAN is III; thus, it is worth promoting.

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.

Headless screw fixation through the dorsal rough surface for proximal-pole scaphoid-nonunion: a report of 15 patients

Clinical outcomes of the dorsal-retrograde headless screw-fixation technique in 15 patients with proximal scaphoid nonunion are presented. In this technique, screws are inserted from the dorsal rough surface of the scaphoid, located between the dorsal ridge and scaphoid-trapezium-trapezoid joint. Fifteen patients underwent osteosynthesis with this technique with iliac bone graft. Seven patients required primary surgery, and eight patients with a history of failed operation required revision surgery. Among 15 patients, 13 achieved union and two with persistent nonunion were asymptomatic with average follow-up of 24 months (range 14-57). Mean time to union was 20 weeks (range 12-40). Our experience with the dorsal-retrograde headless screw fixation technique has shown encouraging results for the treatment of proximal-scaphoid nonunion, especially in revision surgery wherein secure fixation of the small proximal fragments can be difficult using conventional anterograde techniques.Level of evidence: IV.

The Effect of Intra-carpal Kirschner Wire Augmentation in Screw Fixation of Scaphoid - A Retrospective Cohort Study

Introduction:

Scaphoid fractures are most often treated with a single headless compression screw. However, intercarpal Kirschner wire (K-wire) might be added to improve stability and fracture outcomes. This study will determine if there is a difference in treatment outcome (union rate and time to union) between scaphoid fracture fixations using a single headless compression screw with and without augmentation using a intracarpal intramedullary K-wire.

Material and Methods:

We conducted a retrospective review of patients who underwent surgery for isolated scaphoid fractures over a 15 years period from December 2000 to December 2015. Only patients who underwent open surgery with bone grafting were included. They were divided into a group treated with a single screw fixation, and another group treated with screw and K-wire fixations.

Results:

Forty-four (58.7%) patients had single screw fixation and 31 (41.3%) had screw augmented with K-wire fixation. The overall union rate was 88.0%, with an overall mean time to union of 5.3 months. There was no difference in union rate (p=0.84) and time to union (p=0.66) between the single screw group and combined screw and K-wire group. Univariate analysis found that older age (t=-2.11, p=0.04) had a significant effect on union rate. Regression model showed that age had a significant effect on months to union.

Conclusion:

In open fixation of scaphoid fractures with compression screw and bone grafting, union rate and time to union is comparable whether or not screw fixation was augmented with an intracarpal K-wire. There was no increased risk of complications associated with augmented screw. Age of patient affected time to union and union rate.

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.

Approach to the Perpendicular Fixation of a Scaphoid Waist Fracture-A Computer Analyzed Cadaver Model

PURPOSE

In scaphoid fracture screw fixation, the screw is commonly placed along the long axis of the bone, without consideration of the fracture plane. This position is not perpendicular to transverse waist fractures or to the more common horizontal oblique fractures. Our aim was to examine the feasibility and describe possible approaches to, placing a screw perpendicular and in the center of the scaphoid waist fracture.

METHODS

Computed tomography of 12 cadaver wrists was performed in 3 positions to examine possible approaches in flexion, neutral, and extension of the wrist. The scans were evaluated using a 3-dimensional model that simulated horizontal oblique (60°) and transverse (90°) fractures. We examined all possible approaches for screw positioning and their deviation from the axis perpendicular to the fracture and in the center of its plane.

RESULTS

The preferred approaches for a perpendicular screw in a horizontal oblique fracture were found to be proximal-dorsal in flexion or transtrapezial in the extended or neutral positions (through the volar-radial trapezium). In transverse fractures, the possible approaches were proximal-dorsal or transtrapezial in the flexed or neutral positions and distal in the extended position (volar to volar-radial trapezium). In these approaches, the screw could be placed perpendicularly (deviating by < 10°) and in the center of the fracture in all specimens.

CONCLUSIONS

According to this model, it appears feasible to place a perpendicular screw in the center of a horizontal oblique waist fracture using a proximal-dorsal approach in flexion or a transtrapezial approach in neutral or extension positions of the wrist. Palpable landmarks may be used as additional guides to direct these approaches according to the clinical setting.

CLINICAL RELEVANCE

Perpendicular screw fixation of horizontal oblique or transverse scaphoid waist fractures is a possible option, if chosen for its biomechanical advantages.

The Vascularity and Osteogenesis of a Vascularized Flap for the Treatment of Scaphoid Nonunion: The Pedicle Volar Distal Radial Periosteal Flap

Background: Vascularized periosteal flaps from the distal radius have been previously proposed. The purpose of this study was to investigate the vascularity and osteogenic potential of a vascularized volar distal radial periosteal flap for the treatment of scaphoid nonunion. Methods: In 5 fresh frozen cadavers, a rectangular periosteal flap was elevated from the distal radius with the pedicle just proximal to the watershed line. Latex dye was injected into the radial artery proximally and the vascularity of the flap characterized by microscopic evaluation. Patients with scaphoid nonunion were then treated with open reduction, internal fixation, and distal radius cancellous bone graft. Two groups of patients with midwaist nonunion scaphoid were then evaluated. The first group received the vascularized periosteal flap and the second group received a nonvascularized periosteal flap. A third group of proximal pole nonunions also received the vascularized flap. Results: Cadaveric dissections revealed that all of the injected flaps demonstrated vascularity to the distal edge of the flap. Vascularized flaps formed visible bone on imaging in 55% of cases. None of the nonvascularized flaps formed visible bone. In group 1, 12/12 midwaist nonunions united. In group 2, union was achieved in 6/6 of patients who completed the follow-up. In group 3, 6/7 proximal pole fractures united. Conclusions: Previously proposed vascularized periosteal flaps from the distal radius appear to possess notable osteogenic potential that may be of interest to surgeons treating scaphoid nonunion.

Scaphoid specific volar locking plate and non-vascularised iliac crest bone graft in scaphoid non-union. A comparative cohort study

Scaphoid non-union develops in 10% of scaphoid fractures. There is sparse literature on fixation methods other than screws. We compared union rates following fixation of scaphoid non-union using screw fixation and a novel method of plate fixation. Retrospective study. Union rates were assessed at 3 months post-operatively by a musculoskeletal radiologist. 15 patients underwent screw fixation and 15 underwent plate fixation. 86% union rate with screw fixation and 72% plate fixation united. There was no significant difference. Screw fixation and plate fixation in our institution both provide union rates that are consistent with the literature.

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.

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.

Volar Plate Fixation to Treat Scaphoid Nonunion: A Case Series With Minimum 3 Years of Follow-Up

PURPOSE

Several options exist for treating scaphoid nonunion. For selected cases, some authors recommend using a volar buttress plate. The aim of the study was to report the clinical and radiological outcomes achieved at a minimum of 3 years' follow-up of treating scaphoid nonunion with a scaphoid volar plate.

METHODS

We retrospectively reviewed 15 patients with symptomatic scaphoid nonunion treated with scaphoid plate osteosynthesis and a bone graft from the volar aspect of the distal radius between January 2011 and November 2013. The patients' average age was 32 years (range, 21-62 years). No patient had undergone previous scaphoid surgery. Clinical assessments included wrist range of motion (ROM), grip strength, and a 10-point visual analog scale rating of pain. Further subjective assessment was performed using validated measurement tools. All patients underwent plain radiography with 6 different views and computed tomography before and after surgery. The scapholunate angle was measured to evaluate carpal alignment.

RESULTS

The mean follow-up period was 42 months (range, 36-51 months). Bone union was obtained in 13 of 15 patients (87%) at an average of 5 months (range, 3-8 months) after surgery. Significant improvements in the scapholunate angle and visual analog scale pain score were observed. However, both wrist ROM and grip strength remained significantly decreased relative to the opposite side (62% and 55% of normal, respectively). Four patients experienced hardware complications: plate breakage (1 scaphoid) and screw back-out (3 scaphoids). Impingement between the radial styloid and the scaphoid plate was identified in 6 patients. Five patients required additional surgery to remove the plate.

CONCLUSIONS

Our study indicates unsatisfactory results treating scaphoid nonunion with a volar scaphoid plate. Although the rate of union was comparable with that of other series, we noted more complications. We are concerned about both the high proportion of hardware complications and required secondary surgical procedures.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

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

PURPOSE

Union of a scaphoid fracture after fixation is influenced by various factors, one of which is fracture stability. This study aims to compare the biomechanical stability of 3 different types of scaphoid fracture fixation in a scaphoid nonunion model.

METHODS

Thirty cadaveric scaphoid specimens were assigned to one of 3 different fixation groups: (1) single 3.0-mm compression screw, (2) two 2.2-mm screws, and (3) scaphoid plate. A 3-mm volar wedge osteotomy was created at the scaphoid waist to simulate a nonunion model. The primary outcome measure was load to failure, whereas secondary outcome measures were load to 2-mm displacement, energy absorbed, stiffness, and mode of failure, recorded by video and retrieval analysis.

RESULTS

There was a significantly lower load to failure in the single screw construct compared with that in the double screw (mean difference 187.2 N) and plate fixation constructs (mean difference 150.7 N). The mean load to 2-mm displacement in the single screw construct (91.5 N) was also significantly lower than that in the double screw (181.8 N) and plate fixation constructs (197.2 N). There was a significantly lower stiffness with the single screw fixation compared with that of the double screws (mean difference 85.4 N/mm), and lower energy absorbed with single screws when compared with that of double screws (mean difference 386.5 mJ) and when compared with plate fixation (mean difference 270.8 mJ).

CONCLUSIONS

In this biomechanical study comparing fixation methods using a model of scaphoid nonunion with bone loss, we found that double screws or plate fixation demonstrated significantly greater stability, stiffness, and energy absorption when compared with a single compression screw. We found no discernible differences between double screw fixation and the plate groups.

CLINICAL RELEVANCE

The use of double screws or plate fixation in a nonunion setting may allow accelerated rehabilitation without compromise to fracture stability.

Scaphoid nonunion: what is the role of the Zaidemberg 1,2 intercompartmental supraretinacular arterial flap?

The reported results for the treatment of scaphoid nonunions with non-vascularized grafts are based on observational studies with a high variability in union rates from 38%-100% and time to union from 6-18 weeks, and there is also a lack of a standard classification. Meta-analyses and systematic reviews have been presented to better support conclusions from large pools of data (604 to 5246 cases), but their interpretation remains limited because of lack of uniformity in the studies analysed. Several authors have presented results from the Zaidemburg flap, with highly variable outcomes despite using the same technique; union rates have ranged from 27%-100% achieved between 6.5-19 weeks. Technical details that may be responsible for the discrepancies are discussed. There is a need for a validated prognostic classification system for scaphoid nonunions that can allow comparisons between outcome studies.

Open reduction and internal fixation of comminuted patellar fractures with headless compression screws and wiring technique

BACKGROUND

Management of a displaced comminuted patellar fractures is challenging, and various surgical fixation methods have been suggested. However, issues of loss of reduction and breakage of fixatives have not yet been resolved. In the current study, we describe a new technique for exposure and stabilization of comminuted patellar fractures and evaluate the clinical and radiologic outcomes of this new treatment.

MATERIALS AND METHODS

Thirteen patellar fractures with articular comminution, which were treated by headless compression screws with additional separate vertical wiring were enrolled in this study. Loose articular fragments were fixed with headless compression screws under direct visual reduction of the articular surface, which was facilitated by the superior everting of the patella. Radiographs of the knee were obtained at routine follow-up to assess fracture healing and widening of articular step-off. Clinical outcomes including range of motion, quadriceps circumference, visual analog scale (VAS) related pain score, Lysholm, and Bostman grading scales were measured at the last follow-up.

RESULTS

All the fractures healed at a mean of 15 weeks. No patient had loss of reduction, evidence of implant migration, or metallic failure. Articular step-off larger than 2 mm was not seen in any of the cases. The average range of motion arc was 134.2° (range, 120°-145°), and the mean Lysholm and Bostman scores were 94.4 (range, 84-100 points) and 28.7 (range, 25-30 points), respectively. Thigh muscle wasting was observed in four patients (33.3%), but no patient had >1.5 cm difference in thigh circumference girth between the injured and uninjured lower limbs. The average VAS-related pain score was 0.4.

CONCLUSIONS

Articular fixations with headless compression screws under direct visual reduction of the articular surface resulted in good clinical outcomes and were considered clinically effective for comminuted patellar 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.

Management of Scaphoid Fractures

LEARNING OBJECTIVES

After reading this article, the participant should be able to: 1. Understand the epidemiology, classification, and anatomy pertinent to the scaphoid. 2. Appropriately evaluate a patient with suspected scaphoid fracture, including appropriate imaging. 3. Understand the indications for operative treatment of scaphoid fractures, and be familiar with the various surgical approaches. 4. Describe the treatment options for scaphoid nonunion and avascular necrosis of the proximal pole.

SUMMARY

The goal of this continuing medical education module is to present the preoperative assessment and the formation and execution of a surgical treatment plan for acute fractures of the scaphoid. In addition, secondary surgical options for treatment of scaphoid nonunion and avascular necrosis are discussed.

Three-dimensional comparison of alternative screw positions versus actual fixation of scaphoid fractures

PURPOSE

The recommended technique for the fixation of a scaphoid waist fracture involves a headless compression screw placed in the proximal fragment center. This is usually accomplished by placing a longitudinal axis screw as visualized by fluoroscopy. The screw length has been shown to have a biomechanical advantage. An alternative to these options, which has been debated in the literature, is a screw placed perpendicular to the fracture plane and in its center. The perpendicular screw may have a biomechanical advantage despite the fact that it may be shorter. This study examined the differences in location and length in actual patients between a screw in the center of the proximal fragment with a longitudinal axis screw, and the actual fixating screw. These were then compared to a perpendicular axis screw.

METHODS

Pre- and post-operative CT scans of 10 patients with scaphoid waist fractures were evaluated using a 3D computer model. Comparisons were made between the length, location and angle of actual and virtual screw alternatives; namely, a screw along the central third of the proximal fragment (central screw axis) where the scaphoid longitudinal axis was calculated mathematically (longitudinal screw axis) and a screw placed at 90° to the fracture plane and in its center (perpendicular screw axis).

RESULTS

The longitudinal axis screw was found to be significantly longer than the other axes (28.3mm). There was a significant difference between the perpendicular axis screw and the location and angle of the other screw axis, but it was only shorter than the longitudinal screw (23.6mm versus 25.5mm for the actual screw; ns.).

CONCLUSIONS

A computed longitudinal axis screw is longer than a central or actual screw placed longitudinally by visual inspection by the surgeon. Although it needs to be placed using computer assisted (CAS) techniques, it may have the biomechanical advantages of a longer screw in a similar trajectory. The perpendicular screw was found to be significantly different in position and angle but not shorter than the actually placed screw. It has biomechanical advantages and does not require visualization with CAS methods, making it the more attractive alternative.

Scaphoid Plate Fixation and Volar Carpal Artery Vascularized Bone Graft for Recalcitrant Scaphoid Nonunions

PURPOSE

We sought to evaluate the clinical and radiographic outcomes after treatment of symptomatic, recalcitrant scaphoid nonunions using a novel combination of volar scaphoid buttress plating with a pedicled vascularized bone graft.

METHODS

We retrospectively followed 9 patients with recalcitrant scaphoid waist nonunions, characterized by failed prior surgery, long duration of nonunion, avascular necrosis of the proximal pole, or considerable bone loss at the nonunion site. We treated these persistent nonunions through a single volar incision with a pedicled vascularized bone graft, based on the volar carpal artery, and a 1.5-mm precontoured, scaphoid-specific, volar buttress plate. Postoperatively, we assessed objective and subjective outcomes as well as radiographs and computed tomography scans.

RESULTS

The median duration of nonunion was 15 months, ranging from 6 to 96 months. Postoperative follow-up ranged from 11 to 19 months. Computed tomography scans demonstrated union in 8 of 9 cases. Complications included 1 minor hematoma that spontaneously resolved. One scaphoid failed to unite, requiring revision surgery. Three patients experienced problems with the plate. One plate was removed from a patient who noted persistent clicking, and 2 plates have caused symptomatic clicking, likely requiring future removal. Eight of nine patients reported satisfaction with the procedure, with QuickDash scores averaging 8.2.

CONCLUSIONS

We present a series of recalcitrant scaphoid nonunions treated with a novel technique of volar buttress plating and vascularized bone graft. In this series, we found a high rate of union, with consistent radiographic improvement and symptomatic relief. This procedure can be performed using a single incision and with minimal donor site morbidity. Volar plating of a scaphoid nonunion comes with the risk of articular prominence, but offers a new alternative to headless screw fixation. Our early results from this series are promising and support this protocol as a viable alternative for challenging nonunions.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Mechanical Evaluation of Four Internal Fixation Constructs for Scaphoid Fractures

BACKGROUND

The objective of this study was to compare the mechanical performance of 4 different constructs for fixation of oblique scaphoid fractures.

METHODS

Twenty-eight synthetic scaphoids underwent an oblique osteotomy along the dorsal sulcus. Each was randomly assigned to fixation by 1 of 4 methods: two 1.5-mm headless compression screws, one 2.2-mm screw, one 3-mm screw, or a 1.5-mm volar variable-angle plate. After fixation, scaphoids were potted at a 45° angle and loaded at the distal pole by a hydraulically driven mechanical testing system plunger until the fixation failed. Excursion and load were measured with a differential transformer and load cell, respectively. From these data, the stiffness, load-to-failure, and maximum displacement of each construct were calculated.

RESULTS

The 2.2-mm screw demonstrated the highest stiffness and the two 1.5-mm screws had the lowest. However, there were no significant differences among the fixation methods in terms of stiffness. Both 2.2- and 3-mm screw constructs had significantly higher loads-to-failure than two 1.5-mm screws. The maximum load for the plate approached, but did not achieve, statistical significance compared with the 1.5-mm screws. There was no significant difference among constructs in displacement.

CONCLUSIONS

All constructs demonstrated similar mechanical properties that may provide sufficient stability for effective clinical use. Given their significantly higher loads-to-failure, a 2.2- or 3-mm screw may be superior to two 1.5-mm screws for fixation of unstable scaphoid fractures. The volar plate did not have superior mechanical characteristics to the compression screws.

Hybrid Russe Procedure for Scaphoid Waist Fracture Nonunion With Deformity

PURPOSE

To assess the results of a hybrid Russe procedure using a corticocancellous strut, cancellous autologous nonvascularized bone graft, and cannulated headless compression screw to reduce the deformity reliably from a collapsed scaphoid nonunion, provide osteoinductive stimulus, and stabilize the fracture for predictable union.

METHODS

A hybrid Russe procedure was performed for scaphoid waist fracture nonunions with humpback deformity and no evidence of avascular necrosis. A volar distal radius autologous bone graft was harvested and a strut of cortical bone was fashioned and placed into the nonunion site to restore length and alignment. We packed cancellous bone graft in the remainder of the nonunion site and fixed the scaphoid was with a headless compression screw. Union was determined by radiographs or computed tomography, and intrascaphoid, scapholunate, and radiolunate angles were calculated on final radiographs. We recorded wrist range of motion, grip strength, pinch strength, pain, and complications.

RESULTS

Fourteen male and 3 female patients (average age, 32 years; range, 16-78 years), with a mean follow-up of 32 months, were examined clinically and radiographically. All 17 scaphoids united with a mean time for union of 3.6 months. The mean postoperative intrascaphoid angle was significantly reduced from 65° preoperatively to 35° postoperatively. The mean radiolunate angle was significantly improved from 20° from neutral (lunate tilted dorsally) preoperatively to 0° postoperatively. The scapholunate angle also demonstrated significant improvement from 70° preoperatively to 56° postoperatively. Grip strength improved from 70% of the contralateral hand to 89% after the procedure. All patients were satisfied with the functional outcome and no donor site morbidity or hardware issues were identified.

CONCLUSIONS

This straightforward hybrid Russe technique predictably restored radiolunate, scapholunate, and intrascaphoid angles with a 100% union incidence. The technique provides excellent functional results in patients with a challenging clinical problem, and we recommend it for scaphoid fracture waist nonunions with dorsal intercalated segment instability deformity.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

A new variant of scaphoid reconstruction: Treatment of scaphoid non-union with avascular bone interponate and high compression screw (Synthes(®))

Scaphoid fractures as frequently overseen injuries often result in scaphoid non-unions, that need to be treated to prevent carpal collapse and secondary cartilage damage. Vital bone tissue and compression of fracture and bone graft ends seem to be crucial in for ossification and final bone healing. In the present study we compare our results using a high compression screw (HCS Synthes^®) to results in the literature using different kinds of internal fixation including compression screws of various types. We present 22 patients with scaphoid non-unions treated with a bone graft and a HCS Synthes^®. We evaluated our post-operative results. The Manchester-Modified Disability of the Shoulder, Arm and Hand–Score (M-Dash) imposed with an average of 29.8 points (MD=29 / SD=9.46 / MIN=18 / MAX=48). None of the re-evaluated patients sorrowed for pain in rest. Five patients stated pain (ranging from 4 to 8 on numeric analogue scale) after heavy burden (e.g. boxing, weight lifting).In exploring the range of motion of the operated hand we deliver the following results: dorsal extension: average 72.73° (MD=80° / SD=17.23° / MIN=30° / MAX=85°), flexion: average 73.64° (MD=80° / SD=8.97° / MIN=60° / MAX=80°), ulnar deviation: average 39.09°, (MD=40° / SD=2.02° / MIN=35° / MAX=40°), radial deviation: average 29.09°, (MD=30° / SD=3.01° / MIN=20° / MAX=30°). Additionally a performance testing was conducted: fist clenching sign: complete without pain in 100%, pinch grip: complete in 100%, moderate pain in n=1 (8.33%), opposition digitus manus I–V complete in 100%, moderate pain n=2 (16.67%). Three patients with persisting fracture gap had a scaphoid bone fractured in the proximal third; one patient even with a very small proximal fragment. One persisting non-union was localized in the middle third (period between injury and operation = 5 years). In conclusion, our patients showed better healing rates compared to results presented in the literature. Non-unions localized in the proximal third of the scaphoid did not seem to benefit using this technique.

Dorsal Plating of Unstable Scaphoid Fractures and Nonunions

Achieving stable fixation of displaced acute and chronic nonunited scaphoid fractures continues to be a challenge for the treating surgeon. The threaded compression screw has been the mainstay of treatment of these fractures for the last 3 decades; however, persistent nonunion after screw fixation has prompted development of new techniques. Recent results of volar buttress plating have been promising. We describe a novel technique of dorsal scaphoid plating. In contrast to volar plating, the dorsal plate is biomechanically more favorable as it utilizes the tension side of the scaphoid bone for dynamic compression. Dorsal scaphoid plating provides a more stable construct than the traditional Herbert screw and mitigates the need for vascular or corticocancellous bone grafting in most cases.

Modified Murray Technique for Carpal Navicular Nonunion

The authors report the results of long-term follow-up in 29 patients treated for non-union of the carpal navicular with a modified Murray technique performed through a lateral approach. Mean patient age at surgery was 22.5 years. Average time from injury to surgery for nonunion was 18 months. In 5 cases, mild signs of osteoarthritis of the radioscaphoid joint (scaphoid nonunion advanced collapse [SNAC] stage I) were present before surgery, and in 2 cases, radiographic signs of avascular necrosis of the proximal nonunion fragment were evident. In all cases, a corticocancellous nonvascularized bone graft taken from the distal part of the ipsilateral radius was used. Mean follow-up was 11.2 years. Nonunion had healed in 93.1% of cases. At follow-up, the 2 patients in whom nonunion had not healed had severe painful osteoarthritis of the wrist (SNAC stage IV). Twenty patients were asymptomatic, and 5 had occasional pain in the wrist. Wrist range of motion was restricted in all patients compared with the contralateral side. Mild osteoarthritis was observed in 6 patients (SNAC stage I). The average Disabilities of the Arm, Shoulder and Hand score was 8.7 of 100. The modified Murray technique is reliable for treating nonunion of the carpal navicular. The union rate is high, and the incidence of wrist osteoarthritis is low compared with other studies. Early diagnosis and treatment of nonunion (a short interval between fracture and surgery) can minimize the risk of degenerative joint disease. Avascular necrosis of the proximal fragment is not an absolute contraindication to surgery.