The Scaphoid Staple: A Systematic Review

Arthroscopic assisted versus open non-vascularized bone grafting in delayed union and nonunion of the scaphoid: a systematic review and meta-analysis

BACKGROUND

Delayed union and nonunion of the scaphoid is a common complication often requiring surgical reconstruction and bone grafting. Our goal was to systematically assess the healing time and clinical outcomes following arthroscopic-assisted versus open non-vascularized bone grafting of the scaphoid.

METHODS

A comprehensive search of the MEDLINE, Embase, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and Cochrane Central databases was completed from inception to September 2023. We included randomized trials and observational studies that reported outcomes following scaphoid delayed union/nonunion comparing arthroscopic-assisted vs. open non-vascularized bone grafting. Two reviewers independently extracted data and assessed the risk of bias. One investigator assessed certainty of evidence and a senior investigator confirmed the assessment. We pooled effects using random-effects models, when possible, for all outcomes reported by more than 1 study.

RESULTS

Overall, 26 studies and 822 patients were included in the study. Very low certainty evidence demonstrated that arthroscopic-assisted surgery may decrease healing time compared to open surgery (weighted mean difference [WMD] -7.8 weeks; 95%CI -12.8 to -2.8). Arthroscopic bone grafting did not result in an improvement in union rate (relative risk 1.01; 95%CI 0.9 to 1.09). The pooled data in arthroscopic graft group showed mean time to union of 11.4 weeks (95%CI: 10.4 to 12.5) with union rate of 95% (95%CI 91-98%). A single comparative study reported very low certainty evidence that arthroscopy-assisted vs. open surgery may not have an effect on pain relief (MD 0 cm, 95%CI -0.4 to 0.5 on VAS 10 cm for pain) or improving function (MD -1.2, 95% CI -4.8 to 2.3 on 100 points DASH).

CONCLUSION AND FUTURE DIRECTIONS

Our results suggest that arthroscopic-assisted non-vascularized bone grafting may be associated with improved average weeks to heal in comparison with open surgery for scaphoid delayed union/nonunion reconstruction with overall comparable union rates. There is insufficient evidence to assess the effects of arthroscopic-assisted reconstruction on union rate, time to union, and patient-reported outcomes in patients with other important nonunion characteristics such as established humpback deformity.

Arthroscopic surgery for scaphoid nonunion: a 10-year systematic literature review

The purpose of the study was to investigate whether arthroscopic treatment of carpal scaphoid nonunions by osteosynthesis with bone grafting represents a successful surgical technique. This systematic literature review, conducted following the PRISMA guidelines, explores the past 10 years of clinical studies concerning the arthroscopic treatment of scaphoid nonunions. The most relevant keywords were used to search the databases, and the Downs and Black 27-item checklist has been used as quality assessment tool. Twelve papers that meet the premised eligibility criteria have been identified. These studies demonstrate the efficacy of this surgical solution, achieving a postoperative union rate of 96% in the average time of 13.5 weeks. Regardless of the method of synthesis and the origin of the graft used, excellent results were obtained. Patients who underwent this procedure reported a pain reduction of almost 80% compared to the preoperative level, improvement in grip strength close to 40%, and recovery in wrist function during daily activities. Arthroscopy has numerous advantages compared to the open approach. These are technically recognized by the surgeon and by the patient. Some disadvantages include a longer intraoperative time and considerable significant technical difficulty. Arthroscopic treatment of scaphoid nonunion by osteosynthesis with bone graft achieves a 96% union rate of the treated scaphoid with satisfying clinical results.

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.

The history of orthopaedic use of nitinol compression staples

INTRODUCTION

The use of nitinol continuous compression staples has shown clinical utility in the management of various orthopaedic injuries. While literature is most robust in the realm of foot/ankle and spine surgery, the use of nitinol staples has been documented in fixation of wrist, olecranon, patella, and pelvis fractures.

METHODOLOGY

A narrative review was conducted by searching three online databases - PubMed, Web of Science, and Cochrane using the terms "Nitinol" and "Staple" published between 2003 and 2023. A total of 42 articles met inclusion/exclusion criteria and were included in this review.

REVIEW

Literature outside of foot/ankle and spine surgery is largely limited to biomechanical studies, case reports, and finite element analyses. The literature is summarized within this review by anatomic location including foot/ankle, lower extremity, hand, upper extremity, spine, and pelvis.

CONCLUSION

Existing literature demonstrates a diverse array of applications for nitinol continuous compression staples in both axial and appendicular orthopaedic care. Advantages of these implants include ease of application, ability to capture small bony fragments, continuous compression across a fracture or arthrodesis, and full coaptation which maximizes the surface area for healing and/or fusion.

Staple Technology for Fracture Fixation and Joint Arthrodesis

The use of staple technology in the upper extremity has continued to evolve with the development of shape-memory alloys (SMAs) such as Nitinol that display superelastic properties that can be exploited for persistent compression. Clinical and biomechanical studies support the use of SMA staples for upper extremity fracture fixation and joint arthrodesis. To optimize biomechanical strength and clinical outcomes, it is recommended to place two staples, if possible, at the site of interest as well as to trough the staples to prevent hardware prominence.

Using shape-memory alloy staples to treat comminuted manubrium sterni fractures: A case report

BACKGROUND

Comminuted manubrium sterni fractures are rare, and internal fixation methods are limited. This report explored a practical and feasible method of internal fixation for comminuted manubrium sterni fractures.

CASE SUMMARY

A 17-year-old female was injured in a car accident for which she underwent debridement and suturing of her head and anterior chest wounds in another hospital. Eight days later, the patient was transferred to our hospital for surgical treatment. The manubrium sterni was found intraoperatively to be split into three irregular fragments with obvious overlap and separation displacement. Meanwhile, a manubriosternal joint dislocation and left first rib cartilage fracture were observed. The retraction force of the shape-memory alloy staples was used to pull the fracture fragments together. Two more titanium locking plates were then used to fix the manubrium sterni and corpus sterni longitudinally, and the left first rib cartilage fracture was repositioned and fixed with a titanium locking plate. A postoperative computed tomography scan showed reduced and rigid fixation of the comminuted manubrium sterni fractures. The patient recovered well with no significant complaints of discomfort. The patient was discharged 10 days postoperatively after the stitches had been removed.

CONCLUSION

Shape-memory alloy staples had the advantage of being safe and effective during the repositioning and internal fixation of comminuted manubrium sterni fractures. Therefore, they provided a new surgical option for comminuted manubrium sterni fractures.

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.

The Use of Shape-Memory Alloy Staples (Nitinol) in the Treatment of Pubic Symphyseal Disruptions: Clinical Results and Radiographic Outcomes

Nitinol is a shape-memory alloy that has many diverse applications in the field of orthopedics. There have been no previous investigations reporting clinical or radiographic outcomes of the use of nitinol staples in the definitive stabilization of the pubic symphysis. A retrospective chart review was completed on 42 patients who underwent operative stabilization of pubic symphyseal disruption at an urban level-1 trauma center. Patients treated with pelvic staples alone, or in conjunction with traditional plates and screws, were compared with those treated without the use of a shape memory alloys. Thirty-four patients were included for final analysis (8 staples and 26 controls) in this investigation. Three of eight patients in the pelvic staple group had implant failures, with two having a loss of reduction (25%); this was not significantly different from the seven hardware failures (P = 0.61) seen in the control group without any loss of reduction (P = 0.17). Failures in the nitinol staple group occurred earlier at 17.3 days compared with the control group at 101.7 days (P = 0.003). There were no significant differences between groups with regards to any of the other pre- or postoperative variables investigated. The use of nitinol staples vs. traditional plate and screw constructs for stabilizing the pubic symphysis did not result in more clinical failures. The hardware failures identified in the nitinol staple group occurred significantly earlier in the postoperative period, and were associated with a loss of reduction of the pubic symphysis.

The progress in the classification and treatment of scaphoid nonunion

Scaphoid fracture is the most common carpal fracture, accounting for 50%-80% of all carpal fractures in the Youngers and manual workers. The nonunion rate of scaphoid fractures was approximately 10-15%. Scaphoid nonunion can lead to wrist deformity, wrist collapse, ischemic necrosis, and traumatic osteoarthritis resulting in the loss of wrist function and seriously influence the patients' lives. Achieving bony union is essential for the treatment of scaphoid nonunion. Although many surgical procedures including various forms of bone grafting have been developed to improve bony union, there is no conclusion about which method is the most effective and optimal. In this review, we provide an overview of the diagnostic, classification and progress in the treatments of scaphoid nonunion fractures.

Salvage Fixation With a Single Nitinol Compression Staple for a Lateralized Fibular Tunnel in Posterolateral Corner Reconstruction of the Knee

Recognition and treatment of injuries to the posterolateral (PLC) corner of the knee have increased in recent decades. Despite advancements in surgical technique, complications can occur in up to 20% of PLC reconstructions. Lateralization of the fibular tunnel during drilling is a common intraoperative pitfall and can lead to cortical breach or fibular head fracture after graft tensioning. Compression staples have been increasingly used for fracture fixation in the hand, foot, and ankle. Because of its pseudo-elastic properties, insertion of a low-profile, compressive Nitinol staple could serve as an intraoperative salvage technique to reinforce and prevent failure through a thin lateral cortex of the fibular head. The purpose of this Technical Note is to describe a reproducible technique for the implementation of a Nitinol staple for reinforcement of a lateralized fibular tunnel in posterolateral corner reconstruction.

Scaphoid waist fractures fixation with staple. Retrospective study of a not widespread procedure

INTRODUCTION

In carpal scaphoid fractures, the surgical treatment with screw is considered the gold standard; shape memory staple however presents substantial advantages. The authors report a study on unstable fractures of the scaphoid waist (type B1, B2, B5, according to Herbert classification) treated with shape memory staple on a large sample of patients, with the aim to confirm the usefulness of this method, the quality of reduction and fixation, the functional results, the time of union and the possible complications.

MATERIALS AND METHODS

A retrospective analysis of 131 patients with scaphoid waist fractures with minimum follow-up 1 year was performed. Staples were used in all cases; technical details are discussed. Outcome measures were: postoperative pain, flexion-extension wrist range, hand grip strength, radiographic consolidation, work absence. Herbert and Fisher Grading System was used to assess subjective, objective and radiographic results.

RESULTS

Consolidation was achieved in all cases of primary fractures (0-30 days) within three months after surgery, and within eight months in all but two cases of delayed unions (operated within 6 months of the injury). Pain was absent at follow-up in 79% of cases, never severe or unbearable, the average flexion-extension range achieved was 112°. Handgrip strength values were comparable to those of contralateral wrist in 75% of cases. Mean time lost at work was 7.4 weeks. No algo-distrophy or malunion were observed. Discussion CONCLUSIONS: Scaphoid waist fractures' treatment with shape memory staple should be considered as an excellent alternative to screw fixation.

The Use of Nitinol Compression Staple Fixation and Bone Graft for Scaphoid Waist Fractures and Nonunion: A Surgical Technique

In the management of scaphoid fractures, nonunion is an important complication that can lead to carpal instability and early-onset arthritis. Various techniques have been described to treat scaphoid nonunions, yet a clear consensus on the superiority of one method is not yet established. The use of compression staple fixation has been described in the literature and may be a viable alternative to other fixation techniques. Volar Nitinol staple fixation avoids damage to the trapezium during retrograde fixation with a screw. It also avoids damage to the proximal dorsal cartilage, which occurs during anterograde screw fixation. Because of its shape and position on the volar aspect of the scaphoid, staple fixation provides compression, prevents graft extrusion, and avoids taking up space in the medullary canal of the scaphoid. Moreover, it may be technically easier than screw fixation. Despite these advantages, this technique has not been widely adopted. We describe the technique for utilizing Nitinol compression staples and bone grafting in the treatment of scaphoid nonunion.

Comparison of Shape Memory Staple and Gelled Platelet-Rich Plasma versus Shape Memory Staple alone for the Treatment of Waist Scaphoid Nonunion: A Single-Center Experience

Purpose  The aim of this study was to analyze the results of two different methods of surgical treatment of waist scaphoid nonunions (SNUs). We retrospectively analyzed data from 87 patients referred to our department from January 2010 to December 2017 who were surgically treated for waist SNU.

Methods  The mean period of time passed from trauma was 11.2 (±5.6) months. Patients were divided into two groups based on surgical treatment received: volar exposure osteosynthesis with shape memory staple (SMS) (group A) and volar exposure osteosynthesis with SMS and gelled platelet-rich plasma (GPRP) application at the bone defect level (group B). A cast (thumb excluded) was maintained for 4 weeks. Healing was checked clinically (pain, QuickDASH [Disabilities of the Arm, Shoulder, and Hand] score, Mayo Wrist Score) and radiologically (standard X-ray).

Results  Union was achieved in 40 patients in group A (95.2%) and in all patients in group B (45 patients; 100%). A statistically significant difference was observed in the improvement of the Mayo Wrist Score, QuickDASH score, and pain (measured through the visual analog scale) after 3 months from surgery ( p  = 0.02).

Conclusion  SMS is effective in treating waist SNU at more than 6 months from trauma. GPRP application can improve bone healing and upper limb function.

Level of Evidence  This is a retrospective observational Level III study.

Which Headless Compression Screw Produces the Highest Interfragmentary Compression Force in Scaphoid Fracture?

BACKGROUND

Interfragmentary compression at the fracture site facilitates healing. Headless compression screws used to treat scaphoid fractures can be grouped as shank screws, conical tapered screws and double component screws. There has been no meta-analysis of biomechanical studies to compare interfragmentary compression produced by the above screws.

METHODS

A computerised search of Pubmed, Embase and OVID database was undertaken to identify the studies. We estimated the weighted mean difference of interfragmentary compression (in Newton) with 95% confidence intervals. Random effects model was selected for meta-analysis.

RESULTS

The pooled estimate of nine studies demonstrated that conical tapered screw produced significantly higher interfragmentary compression force compared to the shank screw (WMD 19.96, 95% CI 11.2-28.8, p < 0.0001, I ² = 99%). The pooled estimate of four studies demonstrated that dual component screw produced significantly higher interfragmentary compression force compared to the shank screw (WMD 16.93, 95% CI 12.3-21.6, p < 0.0001, I ² = 97.7%). The pooled estimate of four studies showed that there was no significant difference in the interfragmentary compression force generated by either conical tapered screw or dual component screw (WMD 3.93, 95% CI - 8.3 to 16.2, p = 0.53, I ² = 99.7%). There was evidence of minimal publication bias.

CONCLUSION

Conical tapered screws and dual component screws produced statistically significant higher interfragmentary compression force at the scaphoid fracture site compared to shank screws. There was no difference in the compression force generated by either conical tapered screw or dual component screw.

Imaging the Postsurgical Upper Limb: The Radiologist Perspective

Imaging has a paramount role in postsurgical assessment. Radiologists need to be familiar with the different surgical procedures to be able to identify expected postsurgical appearances and also detect potential complications. This article reviews the indications, normal expected postsurgical appearances, and complications of the most frequently used surgical procedures in the shoulder, elbow, and wrist. The emphasis is on points that should not be overlooked in the surgical planning.

Fracture Fixation Using Shape-Memory (Ninitol) Staples

Shape-memory alloy (SMA) staples are a recent innovation in fracture fixation. These staples have inherent compressive properties that create a stable fracture environment that promotes primary bone healing. They have been used successfully for osteotomies, arthrodesis, and fracture fixation. Understanding where SMA staple compression can be optimized and using proper indications are important for obtaining consistent success and minimizing failures. SMA staples are not a substitute for lag screw fixation or traditional plate and screw constructs.

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.