Bone Grafts for Scaphoid Nonunion: An Overview

Three-Dimensional-Planned Patient-Specific Guides for Scaphoid Reconstruction: A Comparative Study of Primary and Revision Nonunion Cases

Background: Scaphoid reconstruction after an established non- or malunion is challenging and recent developments have shown the feasibility to reconstruct it with 3D-planned and -printed patient-specific instrumentation. Methods: Our study compared the clinical outcome of computer assisted 3D-reconstructions of the scaphoid using patient-specific guides for primary and revision reconstructions of scaphoid nonunion regarding clinical outcome. Therefore, 39 patients with primary scaphoid nonunion or malunion and 15 patients with nonunion or malunion after a previous operative treatment were treated with patient-specific guides and followed up for a mean of 10.5 months. The consolidation was assessed with a CT-scan, and the time to consolidation was recorded. Pain level, satisfaction, wrist range of motion, and grip strength were measured and compared. Results: The wrist range of motion and grip strength of the two groups were similar, except for the wrist extension, which was significantly reduced in the revision group. Consolidation was observed in 36/39 patients (92%) in the primary group and in 13/15 patients (87%) in the revision group. Our results showed similar clinical results postoperatively between primary reconstructions and revision surgery. Conclusions: The use of 3D-planned and -printed patient-specific instrumentation proves to be similarly effective in revision surgeries for the reconstruction of the scaphoid as it is in primary surgeries.

Research Advances and Application Progress on miRNAs in Exosomes Derived From M2 Macrophage for Tissue Injury Repairing

Tissue injury repair is a multifaceted and dynamic process characterized by complex interactions among various immune cells, with M2 macrophages assuming a crucial role. Exosomes derived from M2-type macrophages (M2-Exos) significantly influence the injury repair process through intercellular communication mediated by enriched microRNAs (miRNAs). This review aims to elucidate the biological processes underlying exosome formation, the synthesis and function of miRNAs, and the diverse methodologies employed for exosome extraction. Furthermore, we provide a comprehensive summary of the established multifarious functions and mechanisms of M2-Exos miRNAs in tissue injury repair across different systems, while also exploring their potential applications in disease prevention, diagnosis, and clinical practice. Despite the challenges encountered, the therapeutic use of M2-Exos in clinical contexts appears promising, prompting research efforts to focus on improving the efficiency of exosome extraction and application, as well as ensuring the safety of their clinical utilization.

Concentrated autologous bone marrow injection in the surgical treatment of scaphoid non-union

New surgical techniques for the treatment of scaphoid non-union, developed in the last two decades, now enable a healing rate of 80-90%. However, no consensus exists for the surgical treatment of non-union. On the other hand, regenerative medicine techniques have enriched the therapeutic armamentarium for non-union, especially in the lower limbs, with the use of autologous concentrated bone marrow injection using autologous osteogenic precursors to create a favorable microenvironment for bone healing. This technique has the advantages of being inexpensive, easily accessible and applicable in scaphoid non-union as a biological adjuvant to surgery, to improve both healing times and rates. We report 6-month clinical results for the first patient receiving autologous concentrated bone marrow injection associated to scaphoid screw fixation in our center.

Nonunion scaphoid bone shape prediction using iterative kernel principal polynomial shape analysis

BACKGROUND

The scaphoid is an important mechanical stabilizer for both the proximal and distal carpal columns. The precise estimation of the complete scaphoid bone based on partial bone geometric information is a crucial factor in the effective management of scaphoid nonunion. Statistical shape model (SSM) could be utilized to predict the complete scaphoid shape based on the defective scaphoid. However, traditional principal component analysis (PCA) based SSM is limited by its linearity and the inability to adjust the number of modes used for prediction.

PURPOSE

This study proposes an iterative kernel principal polynomial shape analysis (iKPPSA)-based SSM to predict the pre-morbid shape of the scaphoid, aiming at enhancing the accuracy as well as the robustness of the model.

METHODS

Sixty-five sets of scaphoid images were used to train SSM and nine sets of scaphoid images were used for validation. For each validation image set, three defect types (tubercle, proximal pole, and avascular necrosis) were virtually created. The predicted shapes of the scaphoid by PCA, PPSA, KPCA, and iKPPSA-based SSM were evaluated against the original shape in terms of mean error, Hausdorff distance error, and Dice coefficient.

RESULTS

The proposed iKPPSA-based scaphoid SSM demonstrates significant robustness, with a generality of 0.264 mm and a specificity of 0.260 mm. It accounts for 99% of variability with the first seven principal modes of variation. Compared to the traditional PCA-based model, the iKPPSA-based scaphoid model prediction demonstrated superior performance for the proximal pole type fracture, with significant reductions of 25.2%, 24.7%, and 24.6% in mean error, Hausdorff distance, and root mean square error (RMSE), respectively, and a 0.35% improvement in Dice coefficient.

CONCLUSION

This study showed that the iKPPSA-based SSM exploits the nonlinearity of data features and delivers high reconstruction accuracy. It can be effectively integrated into preoperative planning for scaphoid fracture management or morphology-based biomechanical modeling of the scaphoid.

Symptomatic Heterotopic Bone Formation after 1,2 ICSRA in Scaphoid Nonunions

Background  We observed several cases of heterotopic bone formation after a 1,2 intercompartmental supraretinacular artery (1,2 ICSRA) distal radius vascularized bone graft (VBG) for the treatment of scaphoid nonunion. This adverse event seems underreported. Knowledge about factors associated with the formation of heterotopic bone after VBGs might help reduce this adverse event. Purpose  What factors are associated with resected heterotopic bone formation after 1,2 ICSRA distal radius graft for the treatment of scaphoid nonunion? Patients and Methods  We retrospectively reviewed all patients with a scaphoid nonunion treated with a 1,2 ICSRA distal radius graft between 2008 and 2019 in an urban level 1 trauma center in the Netherlands. We included 42 scaphoid nonunions in 41 people treated with the 1,2 ICSRA graft. We assessed potential correlation with patient, fracture, and treatment demographics. Results  Heterotopic bone developed in 23 VBGs (55% [23/42]), of which 5 (12% [5/42]) were resected. Heterotopic bone was located radially (at the pedicle side) in all participants. Except a longer follow-up time ( p  = 0.028), we found no variables associated with the development of heterotopic bone formation. Conclusion  The location of the heterotopic bone at the pedicle site in all cases suggests a potential association with the periosteal strip. Surgeons might consider not to oversize the periosteal strip as a potential method to prevent heterotopic ossification after VBG. Level of Evidence  Level II, prognostic study.

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.

Patient outcome scores between 1,2- and 2,3-intercompartmental supra-retinacular artery (ICSRA) pedicled vascularised bone grafts (PVBGs) in the treatment of proximal pole scaphoid fracture non-union - a questionnaire study

BACKGROUND

Numerous studies have been published on the use of 1,2-intercompartmental supra-retinacular artery (ICSRA) as a pedicled vascularised bone graft (PVBG) in scaphoid fracture non-union, however, only very few studies have reported their results of 2,3-ICSRA. The aim of this study was to compare the patient-rated outcome scores between these two PVBGs in proximal pole scaphoid fracture non-union.

METHODS

Nineteen patients who underwent surgery for scaphoid non-union between 2017 and 2021 at a single institution were recruited retrospectively in this study. All patients were operated by a one senior orthopaedic surgeon. A mailed questionnaire with the modified mayo wrist (MMW) and the patient rated wrist evaluation (PRWE) scores were sent to the patients.

RESULTS

All patients were males with a mean age of 22.5 years. There was no statistically significant difference in the PRWE score between the two PVBGs. However, a statistically significant difference was found in the MMW score, with the 1,2-ICSRA PVBG having better scores.

CONCLUSION

Despite the 2,3-ICSRA having a longer arc of rotation, longer nutrient arteries, and is technically easier to incorporate in a PVBG, when compared with the 1,2-ICSRA it did not result in better patient-rated outcome scores.

Vascularized Bone Graft Reconstruction for Upper Extremity Defects: A Review

Upper extremity reconstruction may pose clinical challenges for surgeons due to the often-critical, complex functional demands of the damaged and/or missing structures. The advent of vascularized bone grafts (VBGs) has aided in reconstruction of upper extremity (UE) defects due to their superior regenerative properties compared with nonvascularized bone grafts, ability to reconstruct large bony defects, and multiple donor site options. VBGs may be pedicled or free transfers and have the potential for composite tissue transfers when bone and soft tissue are needed. This article provides a comprehensive up-to-date review of VBGs, the commonly reported donor sites, and their indications for the treatment of specific UE defects.

Comparison between Vascular and Non-Vascular Bone Grafting in Scaphoid Nonunion: A Systematic Review

BACKGROUND

Scaphoid fractures correspond to 60% of all carpal fractures, with a risk of 10% to progress towards non-union. Furthermore, ~3% present avascular necrosis (AVN) of the proximal pole, which is one of the main complications related to the peculiar vascularization of the bone. Scaphoid non-union can be treated with vascularized and non-vascularized bone grafting. The aim of the study is to evaluate the rates of consolidation of scaphoid non-union treated using two types of grafts.

METHODS

A systematic review of two electronic medical databases was carried out by two independent authors, using the following inclusion criteria: non-union of the proximal pole of the scaphoid bone, treated with vascular bone grafting (VBG) or non-vascular bone grafting (NVBG), with or without the use of internal fixation, patients aged ≥ 10 years old, and a minimum of 12 months follow-up. Research of any level of evidence that reports clinical results and regarding non-union scaphoid, either using vascularized or non-vascularized bone grafting, has been included.

RESULTS

A total of 271 articles were identified. At the end of the first screening, 104 eligible articles were selected for the whole reading of the text. Finally, after reading the text and the control of the reference list, we selected 26 articles following the criteria described above.

CONCLUSIONS

The choice of the VBG depends mainly on the defect of the scaphoid and on the surgeon's knowledge of the different techniques. Free vascular graft with medial femoral condyle (MFC) seems to be a promising alternative to local vascularized bone grafts in difficult cases.

Outcomes of Pediatric Scaphoid Nonunions Treated With Distal Radius Cancellous Autograft

BACKGROUND

The optimal management of pediatric scaphoid fracture nonunions is controversial. We hypothesize that pediatric patients with scaphoid fracture nonunions will have favorable functional outcomes with the utilization of nonvascularized distal radius cancellous autograft with open reduction and internal fixation (ORIF).

METHODS

A review was performed from 2012 to 2017 identifying skeletally immature patients with scaphoid fracture nonunions treated with ORIF and nonvascularized distal radius cancellous autograft, including demographic data, mechanism of injury, length of time from injury to treatment, operative procedure, length of immobilization, time to union, and complications.

RESULTS

Ten patients (9 males, 1 female) met inclusion criteria. Mean age was 14.3 SD 1.5 years. The majority of fractures were sustained during sports or secondary to a fall. Mean time between injury and orthopaedic evaluation was 33 weeks (SD 20 wk). Eight fractures occurred at the waist, and 2 occurred at the proximal pole. Four patients had a humpback deformity, and three presented with a dorsal intercalated segmental instability deformity. Nine patients were treated with a single cannulated compression screw with distal radius autograft. One patient also received a single Kirschner wire fixation in addition to a single cannulated screw and graft. Patients underwent a mean postoperative immobilization period of 14 SD 5 weeks. Two patients received a bone stimulator postoperatively. Radiographic union was documented after initial surgery in nine patients, with mean time to union of 17 SD 5 weeks. The 1 patient with persistent radiographic nonunion underwent revision fixation and repeat nonvascularized distal radius autograft, achieving union and resolution of symptoms. All patients ultimately reported full return to activity.

CONCLUSIONS

Pediatric scaphoid fracture nonunions that undergo ORIF using nonvascularized distal radius cancellous autograft have favorable rates of consolidation and functional outcomes. Surgeons should consider this source of grafting in operative management of scaphoid nonunions in children and adolescents.

LEVEL OF EVIDENCE

Level IV, therapeutic.

Biopolymer Material from Human Spongiosa for Regenerative Medicine Application

Natural biopolymers demonstrate significant bone and connective tissue-engineering application efficiency. However, the quality of the biopolymer directly depends on microstructure and biochemical properties. This study aims to investigate the biocompatibility and microstructural properties of demineralized human spongiosa Lyoplast® (Samara, Russian Federation). The graft's microstructural and biochemical properties were analyzed by scanning electron microscopy (SEM), micro-computed tomography, Raman spectroscopy, and proteomic analysis. Furthermore, the cell adhesion property of the graft was evaluated using cell cultures and fluorescence microscopy. Microstructural analysis revealed the hierarchical porous structure of the graft with complete removal of the cellular debris and bone marrow components. Moreover, the proteomic analysis confirmed the preservation of collagen and extracellular proteins, stimulating and inhibiting cell adhesion, proliferation, and differentiation. We revealed the adhesion of chondroblast cell cultures in vitro without any evidence of cytotoxicity. According to the study results, demineralized human spongiosa Lyoplast® can be effectively used as the bioactive scaffold for articular hyaline cartilage tissue engineering.

Preoperative Planning Using 3D Printing Technology in Orthopedic Surgery

The applications of 3D printing technology in health care, particularly orthopedics, continue to broaden as the technology becomes more advanced, accessible, and affordable worldwide. 3D printed models of computed tomography (CT) and magnetic resonance image (MRI) scans can reproduce a replica of anatomical parts that enable surgeons to get a detailed understanding of the underlying anatomy that he/she experiences intraoperatively. The 3D printed anatomic models are particularly useful for preoperative planning, simulation of complex orthopedic procedures, development of patient-specific instruments, and implants that can be used intraoperatively. This paper reviews the role of 3D printing technology in orthopedic surgery, specifically focusing on the role it plays in assisting surgeons to have a better preoperative evaluation and surgical planning.

[Treatment of scaphoid non-union: vascularised iliac crest graft or medial femur condyle graft?]

Treatment of scaphoid non-unions is still challenging for responsible hand surgeons, especially in cases of avascular proximal pole non-unions or failed prior surgeries. Several surgical procedures treating scaphoid non-unions have been established. These aim to restore correct anatomy to provide stability and adequate blood flow. Treatment options range from avascular to free, vascularized bone grafts. The two most used free vascularized bone grafts derive from the iliac crest and the medial femoral condyle. The vascular anatomy of the medial femoral condyle graft is more constant, the donor site morbidity lower and the healing rate higher in comparison to the iliac crest graft. It is easier to harvest the femoral condyle graft and additionally, it can be harvested as a cortico-cancellous or osteochondral graft. Looking at all advantage, we come to the conclusion that the free vascularized medial femoral condyle graft is our method of choice for the treatment of a avascular proximal pole non-union of the scaphoid.

Carpal Collapse After Scaphoid Nonunion: A Novel Combined Approach to the 1,2 Intercompartmental Supraretinacular Artery Radial Flap

Purpose

Scaphoid nonunion remains a major problem in hand surgery. The 1,2 intercompartmental supraretinacular artery flap (1,2 ICSRA), as first described by Zaidemberg et al, is widely used with reported union rates of approximately 80%. However, its use is limited in the case of associated carpal collapse as in dorsal intercalated segmental instability (DISI) and humpback deformity. In this study, we present a novel approach to this flap enabling the correction of associated carpal collapse.

Methods

Between 2006 and 2015, 9 patients with scaphoid nonunion or delayed union with carpal collapse were treated with a vascularized bone flap based on the 1,2 ICSRA using a combined volar and dorsal approach. Immobilization in a short-arm cast was applied for 8 weeks. Union rates, correction of DISI and humpback deformity, as well as clinical end points were noted. In addition, scapholunate (SL) angles were measured using 2 accepted radiological techniques, employing either the scaphoid midline axis or its proximal radiological landmarks as a reference.

Results

All cases united and a median time to bone consolidation of 4 months (range, 2–5 months) was observed. Preoperative DISI deformities (n = 4) were corrected in all patients. Humpback deformities (n = 5) were also corrected. Two patients had repeat surgery: one for K-wire removal after bony consolidation and the other for neuropathic pain.

Conclusions

The 1,2 ICSRA bone flap is a reliable treatment for scaphoid nonunion associated with carpal collapse. This combined volar and dorsal approach permits the correction of DISI and humpback deformity without compromising the scaphoid vascular supply, which eliminates the need to use free bone flaps from other sites. In this series, we observed a 100% union rate. Two patients required reoperation for symptomatic hardware and dorsal wrist pain linked to superficial neuritis.

Type of study/level of evidence

Therapeutic IV.

Identification of key microRNAs and target genes for the diagnosis of bone nonunion

A number of recent studies have highlighted the causes of bone nonunion (BN), however, the rate of BN incidence continues to rise and available therapeutic options to treat this condition remain limited. Thus, to prevent disease progression and improve patient prognosis, it is vital that BN, or the risk thereof, be accurately identified in a timely manner. In the present study, bioinformatics analyses were used to screen for the differentially expressed genes (DEGs) and differentially expressed miRNAs (DEMs) between patients with BN and those with bone union, using data from the Gene Expression Omnibus database. Furthermore, clinical samples were collected and analyzed by reverse transcription‑quantitative PCR and western blotting. In vitro and in vivo experiments were carried out to confirm the relationship between BN and the DEGs of interest, in addition to being used to explore the underlying molecular mechanism of BN. Functional enrichment analysis of the downregulated DEGs revealed them to be enriched for genes associated with 'ECM‑receptor interactions', 'focal adhesion', 'and the calcium signaling pathway'. When comparing DEM target genes with these DEGs, nine DEGs were identified as putative DEM targets, where hsa‑microRNA (miR)‑1225‑5p‑CCNL2, hsa‑miR‑339‑5p‑PRCP, and hsa‑miR‑193a‑3p‑mitogen‑activated protein kinase 10 (MAPK10) were the only three pairs which were associated with decreased gene expression levels. Furthermore, hsa‑miR‑193a‑3p was demonstrated to induce BN by targeting MAPK10. Collectively, the results of the present study suggest that hsa‑miR‑193a‑3p may be a viable biomarker of BN.

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.

Does Anyone Need a Vascularized Graft?

Many hand surgeons argue that vascularized bone grafting is indicated in proximal pole avascular necrosis, prior failed surgery, or long-standing scaphoid nonunion. However, the available evidence does not support improved treatment outcomes for vascularized bone grafting rather than traditional nonvascularized techniques. This article addresses the available evidence and examines the role of vascularized bone grafting in scaphoid nonunion treatment. It also identifies important factors that influence healing, clarifies the decision-making algorithm, and proposes areas for further research.

Surgical Strategy for Scaphoid Nonunion Treatment

Scaphoid fracture is the most common carpal fracture. Nonunion rate has been reported around 10 to 15% of scaphoid fractures. Risk factors for scaphoid nonunion are known as location, displacement, poor vascularity, time to treatment etc. The goals of surgical treatment for scaphoid nonunion are to achieve bony union, to correct carpal deformities and also to prevent progressive carpal instability and arthritis. Scaphoid nonunion can cause scaphoid nonunion advanced collapse (SNAC) which is a pattern of progressive degenerative radiocarpal and midcarpal arthritis secondary to posttraumatic pathomechanics of the scapholunate joint. Achieving bony union is essential to prevent carpal collapse or arthritis. To improve bony union, many surgical procedures including various forms of bone grafting have been developed and attempted. However, there is a controversy about which procedure is the most effective. In this review, we provide an overview of surgical treatment methods for scaphoid nonunion and discuss proper surgical strategies for scaphoid nonunion which requires surgical management.

Low-Intensity Pulsed Ultrasound for Nonoperative Treatment of Scaphoid Nonunions: A Meta-Analysis

Background: Scaphoid fractures progress to nonunion rates of up to 15% when non-displaced, and are even more frequent when the fracture is displaced. Standard treatment in these cases is surgery; however, individuals unable to undergo this operation, or for those who wish to try more conservative measures, there may be benefit from nonoperative options. Of these, low-intensity pulsed ultrasound (LIPUS) has been shown to improve fracture nonunion healing. The purpose of this study was to perform a comprehensive meta-analysis of relevant literature to determine success of the use of LIPUS for treatment of scaphoid nonunion. Methods: Utilizing PubMed, Embase, and Ovid databases, we performed a literature search using key terms for scaphoid nonunions. A total of 686 studies met initial search criteria. Studies reporting fewer than 5 cases, those not published in English, those not related to LIPUS nonoperative scaphoid nonunion treatment, and those without sufficient data were excluded. Five studies met these criteria, and statistical analysis was performed to determine overall union rates. Results: The use of LIPUS on 166 nonunions reported a mean healing index of 78.6%. The average time to union following LIPUS treatment was 4.2 months. Conclusions: While surgical intervention is still the standard, our results show that LIPUS may serve as a nonoperative alternative to scaphoid nonunion in certain cases. The results are encouraging in which these challenging fracture a nonunions can heal without further surgical intervention in the majority of patients.

Correlation of CT imaging and histology to guide bone graft selection in scaphoid non-union surgery

INTRODUCTION

For the treatment of scaphoid non-unions (SNU), different surgical techniques, including vascularized and non-vascularized bone grafts, are applied. Besides stability, vascularity, and the biological situation at the non-union site are important for healing and the appropriate choice of treatment. We assessed the healing potential of SNUs by histological parameters and compared it to CT parameters of bone structure and fracture location. Based on the results, we developed a CT classification and a treatment algorithm to impact graft selection in SNU surgery.

PATIENTS AND METHODS

Preoperative 2D-CT reformations of 29 patients were analyzed for trabecular structure, sclerosis, and fragmentation of the proximal fragment. The fracture location was assessed on 3D-CT reconstructions and grouped in three zones depending on the potential blood supply. Samples were taken during surgery for histological evaluation. Histological parameters of bone healing were defined and a bone healing capacity score (BHC), reflecting histological bone viability, was calculated. CT findings were compared to BHC, age of SNU, and time to union.

RESULTS

Cases with trabecular structure and without fragmentation showed a statistically significant higher BHC. Time to union was significantly faster if trabecular structure was present and sclerosis was absent. In intraarticular proximal pole non-unions, where no blood supply is assumed, the BHC was statistically significantly lower and time to union was longer compared to SNUs of the other locations. A statistically significant correlation between BHC and time to union was found in the proximal and distal fragment with higher BHC associated with faster healing.

CONCLUSIONS

CT parameters of bone structure and fracture location can reflect histological healing capacity of SNUs. This can guide bone graft selection in SNU surgery.

Intramedullary Screw and Kirschner Wire Fixation for Unstable Scaphoid Nonunion

Surgical treatment of scaphoid nonunion is not always successful, often requiring stabilization and bone grafting to achieve healing. Even after intramedullary screw fixation, residual instability may still hinder union. The purpose of this study was to describe the addition of Kirschner wires (KWs) through the capitate and the lunate to supplement an intramedullary screw for temporary enhanced stability, possibly improving healing of unstable fractures. A case-control study reviewing 25 cases with addition of KWs and 19 controls was performed. Demographic and fracture information, time to diagnosis, and healing time were documented. We found no differences in population characteristics, fracture characteristics, or outcome measures between patients treated with this method and those treated with a screw alone. We had no complications related to the addition of KWs. Preoperative lunate type and scapholunate gapping was suggestive but not significantly associated with KW insertion. Addition of KWs is safe and may be considered in scaphoid nonunion in the presence of intraoperative suboptimal stability. Intraoperative stability may possibly be inferred by reviewing preoperative radiographs for signs of instability.

[Scaphoid pseudarthrosis : Indications for avascular iliac crest or radius bone grafts]

BACKGROUND

Operative treatment of the scaphoid nonunion includes avascular corticocancellous and cancellous bone grafts and increasingly the use of vascular pedicled and free vascular corticocancellous grafts. Especially the latter require a fair amount of operative expertise and experience in microsurgical techniques.

OBJECTIVE

Which criteria lead to the decision for or against an avascular graft used for reconstruction of scaphoid nonunion? Is our current classification system of a scaphoid pseudarthrosis able to illustrate our diagnostic potential in a way that makes us refer to operative procedures?

METHODS

Evaluation of current literature and expert opinions RESULTS: Avascular bone grafts show a high union rate as long as a sufficient vascularisation of the remaining fragments is present. In general, patients benefit from a very good functional outcome. Even revisions of failed scaphoid union may be successfully treated with an avascular bone graft. Failures of union are repeatedly experienced in treating proximal pole fractures with critical vascularisation or extensive bone loss, especially including avascular necrosis of the proximal pole (AVN). Current classification systems do not allow description and correlation of morphologic findings so as to compare results profoundly and to recommend specific procedures.

CONCLUSIONS

As long as sufficient vascularisation of remaining fragments is seen, the avascular bone graft is eligible for reconstructing scaphoid nonunion. Classification systems do not seem to reflect the status quo of diagnostic possibilities and make it difficult to provide guidelines for state-of-the-art operative procedures.