Femoral Trochlea Osteochondral Autograft Transplant for Scaphoid Proximal Pole Nonunions

Small proximal pole scaphoid nonunions are challenging to treat. We describe a technique for replacing the proximal pole fragment with an osteochondral autograft transplant harvested from the ipsilateral femoral trochlea. This is indicated in nonunions where the proximal pole fragment is smaller than the scaphoid isthmus; the scapholunate ligament complex is intact on the distal fragment, and in nonunions without dorsal intercalated segment instability and radiocarpal arthritis. The osteochondral autograft transplant is press-fitted into the distal scaphoid and does not require implants for osteointegration. This provides an advantage during revision surgery of previously fixed proximal scaphoid fractures that are not united with an implant in situ.

Titanium patient-specific scaphoid replacement for unreconstructable nonunions: a case series study

Although reconstruction is the preferred treatment option for symptomatic scaphoid nonunions, this may not be an option due to inadequate bone quality or degenerative changes. Existing salvage procedures tend to compromise function. This study introduces an alternative approach through the utilisation of a 3-D-printed titanium patient-specific scaphoid implant. In this retrospective case series, the outcomes of 12 patients treated for an unreconstructable scaphoid nonunion with a 3-D-printed prosthesis were evaluated. Patient-reported outcomes, range of motion, grip strength and plain radiographs were assessed pre- and postoperatively. The mean follow-up was 2 years and 8 months. Range of movement and patient-reported outcome scores improved postoperatively, although improvement in movement was not significant. Except for one, all implants showed satisfactory alignment on radiographs without any further degenerative changes. 3-D-printed titanium scaphoid replacement may be an alternative to salvage procedures for unreconstructable scaphoid nonunion.Level of evidence: IV.

High Rate of Union of Scaphoid Pseudoarthrosis Treated With Arthroscopic Olecranon Bone Graft Using Antegrade Percutaneous Headless Compression Screw

PURPOSE

To assess the healing rate of scaphoid pseudoarthrosis treated with wrist arthroscopy, olecranon bone graft, and anterograde screw fixation, as well as evaluate complications and clinical and radiologic outcomes.

METHODS

All patients with scaphoid nonunion were selected between January 2017 and December 2022. Inclusion criteria were patients between 18 and 60 years of age, a diagnosis of scaphoid pseudoarthrosis, complete clinical patient-reported outcomes, radiographic measurements, and at least a 1-year follow-up. Scaphoid pseudoarthrosis was treated arthroscopically with olecranon bone graft and anterograde screw fixation. Clinical assessment was performed through visual analog scale (VAS) for pain, QuickDASH (Disabilities of the Arm, Shoulder, and Hand) questionnaire, wrist range of motion using a standard goniometer, and grip strength in kilograms with a Jamar hydraulic hand dynamometer. Clinical relevance was measured with the minimal clinically important difference (MCID) for VAS and QuickDASH. Scapholunate angle was measured. Union was assessed on a computed tomography scan.

RESULTS

Seventeen patients were included with a mean follow-up of 17.2 months. The mean age was 30.1 years, and the average time from injury to arthroscopic surgery was 11.1 months. At latest follow-up, there was an improvement in VAS pain score and QuickDASH score. Range of motion and grip strength increased at last follow-up. MCID threshold for the VAS and QuickDASH score was reached by 100% and 94.1%, respectively. Union was achieved in 16 patients (94.1%) after a median of 16 weeks (interquartile range, 16-20).

CONCLUSIONS

Arthroscopic treatment of scaphoid pseudoarthrosis with olecranon bone graft and antegrade percutaneous headless compression screw allows a high grade of union and improves pain and function at short-term follow-up.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

The Conservative and Operative Treatment of Carpal Fractures

BACKGROUND

Carpal fractures (incidence: 30-60 per 100 000 persons per year) are one of the more commonly overlooked fracture types. They can have serious consequences, as the use of the hand is indispensable in everyday life. In the following article, we present the elements of the diagnosis and treatment of fractures of the carpal bones.

METHODS

This review is based on meta-analyses and randomized controlled trials (RCTs) published from 2013 to 2023 that were retrieved by a structured literature search, supplemented by guideline recommendations and expert consensus statements. In addition, data on the administrative prevalence of carpal fractures were obtained from the German Association of Statutory Health Insurance Physicians (Kassenärztliche Vereinigung, KV) and from the German Statutory Accident Insurance (Deutsche Gesetzliche Unfallversicherung, DGUV).

RESULTS

The administrative prevalence of carpal fractures in 2022 was 44 496 outpatient cases (KV, DGUV) in one year. After clinical history-taking, physical examination and x-ray have been performed, thin-slice computed tomography is recommended as part of the diagnostic evaluation. Treatment recommendations are based on evidence of levels II to IV. Multiple RCTs have been carried out on the treatment of scaphoid fractures, and a clinical guideline exists. Proximal, dislocated and unstable scaphoid fractures should be treated surgically. Non-displaced or minimally displaced fractures of the middle third of the scaphoid bone require a shorter period of immobilization with surgical treatment (2-4 weeks) than with conservative treatment (6-8 weeks). The use of plaster casts that do not hinder elbow and thumb mobility yields healing rates similar to those obtained with the immobi - lization of both of these joints. Failure to treat an unrecognized scaphoid fracture can lead to pseudarthrosis, avascular bony necrosis, and misalignment. Other, rarer types of carpal fractures must be managed on an individual basis, as the available ev idence is limited to expert consensus.

CONCLUSION

Early recognition and appropriate treatment of carpal fractures lead to healing in more than 90% of cases. Although the available evidence on their proper treatment is growing, many questions are subject to expert consensus, and decisions about treatment must be made individually.

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.

Impact of osteoporosis and osteoporosis medications on fracture healing: a narrative review

Antiresorptive medications do not negatively affect fracture healing in humans. Teriparatide may decrease time to fracture healing. Romosozumab has not shown a beneficial effect on human fracture healing.

BACKGROUND

Fracture healing is a complex process. Uncertainty exists over the influence of osteoporosis and the medications used to treat it on fracture healing.

METHODS

Narrative review authored by the members of the Fracture Working Group of the Committee of Scientific Advisors of the International Osteoporosis Foundation (IOF), on behalf of the IOF and the Société Internationale de Chirurgie Orthopédique et de Traumatologie (SICOT).

RESULTS

Fracture healing is a multistep process. Most fractures heal through a combination of intramembranous and endochondral ossification. Radiographic imaging is important for evaluating fracture healing and for detecting delayed or non-union. The presence of callus formation, bridging trabeculae, and a decrease in the size of the fracture line over time are indicative of healing. Imaging must be combined with clinical parameters and patient-reported outcomes. Animal data support a negative effect of osteoporosis on fracture healing; however, clinical data do not appear to corroborate with this. Evidence does not support a delay in the initiation of antiresorptive therapy following acute fragility fractures. There is no reason for suspension of osteoporosis medication at the time of fracture if the person is already on treatment. Teriparatide treatment may shorten fracture healing time at certain sites such as distal radius; however, it does not prevent non-union or influence union rate. The positive effect on fracture healing that romosozumab has demonstrated in animals has not been observed in humans.

CONCLUSION

Overall, there appears to be no deleterious effect of osteoporosis medications on fracture healing. The benefit of treating osteoporosis and the urgent necessity to mitigate imminent refracture risk after a fracture should be given prime consideration. It is imperative that new radiological and biological markers of fracture healing be identified. It is also important to synthesize clinical and basic science methodologies to assess fracture healing, so that a convergence of the two frameworks can be achieved.

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.

Distal Scaphoid Excision and Dermal Allograft Interposition in a Professional Athlete: Long-term Follow-up

Scaphoid nonunion occurs in 10%-15% of scaphoid fractures, potentially resulting in scaphoid nonunion advanced collapse. Distal scaphoid excision without allograft interposition is a known treatment, but can result in loss of carpal height and pain. This report describes the application of human acellular dermal matrix as an interposition graft after distal scaphoid excision for stage I scaphoid nonunion advanced collapse. Postoperatively, the patient initiated early range of motion and returned to full activity at 6 weeks. He demonstrated resolution of his pain 6 years later.

Clinical, Radiologic, and Functional Outcomes following Bone Grafting for Metacarpal Non-Unions: A Systematic Review

Objectives: Metacarpal non-unions are complex hand defects that can lead to severe hand impairment. Treatment may require the use of artificial or autologous bone grafts. This systematic review aims to describe the outcomes of bone grafting following metacarpal non-union in an attempt to establish an optimal therapeutic protocol for this complication. Methods: A systematic review was conducted in adherence with PRISMA guidelines. Data collection and analysis were performed in duplicate and confirmed by a third investigator. Our primary outcomes focused on radiological time to bone fusion and rates of non-union. Additionally, functional outcomes and complications were analyzed as means of central tendency. Results: Eighteen studies were included in the systematic review, accounting for a total of 47 patients. The average follow-up time was 12.4 months. Fourteen studies analyzed radiological outcomes, with atrophic non-union representing the most common type. The time to bone fusion, assessed radiologically, following bone graft was an average of 6.9 months (n = 14), with a 100% rate of union in 42 patients. Regarding patient-reported pain improvement, 76% of patients experienced pain relief. Moreover, all patients reported a complete subjective return to baseline hand function. Adverse events, limited to hematoma and seroma, were seen in three patients, representing a complication rate of 11.8% in the examined population. Conclusions: Metacarpal non-union can be treated successfully via vascularized and non-vascularized bone grafting. Based on the available evidence, bone grafts demonstrate favorable union rates, post-operative pain reduction, hand function recovery, earlier bone fusion times, and minimal complications in the context of metacarpal non-union management.

Arthroscopic Bone Grafting and Robot-assisted Fixation for Scaphoid Nonunion

OBJECTIVES

Scaphoid nonunion remains a challenging problem to manage with no general consensus on its treatment recommendations. We propose a novel minimally invasive (MIS) technique of arthroscopic bone grafting (ABG) with robot-assisted fixation for the treatment of scaphoid nonunions.

METHODS

Patients with radiographically proven scaphoid nonunion treated by this novel surgical technique were included. Following arthroscopic debridement and iliac crest bone grafting, the scaphoid was fixed percutaneously using either multiple Kirschner (K)-wires or a headless compression screw using a robotic navigation system.

RESULTS

Six male patients with an average age of 29.2 years were enrolled. Four patients had scaphoid waist fractures, and the other two were proximal pole fractures. During wrist arthroscopy, punctate bleeding of the proximal scaphoid fragment was observed in four out of the six patients. Half of the patients were fixed using a headless compression screw and the other half using multiple K-wires. All the guidewires were placed with a single-attempt using the robotic navigation system. Postoperatively, all the scaphoid fractures had complete radiographic union by 16 weeks. At a mean follow-up of 18.3 months, there were significant improvements in wrist range of motion, grip strength, and patient-rated outcomes. No intraoperative or early postoperative complications were encountered in any of our patients.

CONCLUSION

Arthroscopic bone grafting with robot-assisted fixation is a feasible and promising therapeutic option for scaphoid nonunions, regardless of the vascularity of the proximal pole fragment. This novel technique allows for anatomic restoration of the scaphoid alignment and accurate, targeted placement of implants into the scaphoid nonunion site within a single-attempt using a robotic navigation system.

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.

Comparative effectiveness of three treatment options for slade and dodds grade III-IV scaphoid nonunion: a retrospective study

OBJECTIVE

To compare the clinical efficacy of open debridement screw fixation combined with bone grafting, percutaneous screw fixation, and percutaneous screw fixation combined with injection of platelet-rich plasma (PRP) for the treatment of Slade and Dodds Grade III to IV scaphoid nonunion (SNU).

METHODS

This retrospective study included patients with Grade III (25 patients) and Grade IV (28 patients) SNU. They were treated with open surgery bone grafting and internal fixation (group A), percutaneous screw fixation (group B) or percutaneous screw fixation and PRP injection (group C) from January 2015 to May 2020. The fracture consolidation rate, VAS score, and Mayo wrist function score were compared across the three groups.

RESULTS

The consolidation rate was not significantly different among the three groups for both Grade III and IV SNU. However, patients in group C reported significantly less pain and better wrist function 7 days after surgery compared to group A and B, for both nonunion grades. At 3 months after surgery, group C had significantly better VAS and Mayo wrist scores compared to group A for both nonunion grades, and compared to group B for Grade IV SNU. At 6 and 12 months after surgery, patients with Grade IV SNU in groups A and C had significantly better VAS and Mayo wrist scores compared to group B.

CONCLUSION

This study suggests that percutaneous screw fixation with PRP injection could be a more effective method for treating Grade IV SNU. This approach may reduce postoperative wrist pain and improve wrist function in the early stages after surgery for patients with both Grade III and IV SNU.

TYPE OF STUDY/LEVEL OF EVIDENCE

IV.

The promotive role of USP1 inhibition in coordinating osteogenic differentiation and fracture healing during nonunion

BACKGROUND

Nonunion is a failure of fracture healing and a major complication after fractures. Ubiquitin-specific protease 1 (USP1) is a deubiquitinase that involved in cell differentiation and cell response to DNA damage. Herein we investigated the expression, function and mechanism of USP1 in nonunion.

METHODS AND RESULTS

Clinical samples were used to detect the USP1 expression in nonunion. ML323 was selected to inhibit USP1 expression throughout the study. Rat models and mouse embryonic osteoblasts cells (MC3T3-E1) were used to investigate the effects of USP1 inhibition on fracture healing and osteogenesis in vivo and in vitro, respectively. Histological changes were examined by micro-computerized tomography (Micro-CT), hematoxylin & eosin (H&E) staining and Masson staining. Alkaline phosphatase (ALP) activity detection and alizarin red staining were used for osteogenic differentiation observation. The expression of related factors was detected by quantitative real-time PCR, western blot or immunohistochemistry (IHC). It was shown that USP1 was highly expressed in nonunion patients and nonunion rats. USP1 inhibition by ML323 promoted fracture healing in nonunion rats and facilitated the expression of osteogenesis-related factors and the signaling of PI3K/Akt pathway. In addition, USP1 inhibition accelerated osteogenic differentiation and promoting PI3K/Akt signaling in MC3T3-E1 cells.

CONCLUSIONS

USP1 inhibition plays a promotive role in coordinating osteogenic differentiation and fracture healing during nonunion. PI3K/Akt may be the downstream pathway of USP1.

Asymptomatic Nonunion Scaphoid Fracture After Kirschner Wire Fixation of Trans-Scaphoid Lunate Dislocation: A Case Report with 3 Years of Follow-up

Background: Trans-scaphoid lunate dislocation is an orthopaedic injury, mostly because of high energy trauma. Due to subtle clinical and radiological findings, it might be easily left undiagnosed, with estimated 25% cases are missed at initial assessment in emergency department. Non-union scaphoid, which accounts for 5-10% of all scaphoid fractures treated with K-wires fixation, mostly occurs in young and active individual. Case Presentation: Thirty-seven-years-old right-handed man complained pain, and restricted range of motion (ROM) on his right wrist after fell from 2m height. Loss of symmetry and parallelism of joint space in Gilula's line shown in X-ray, possible for a trans-scaphoid lunate dislocation. We performed dorsal approach and internal fixation using Kirschner wire (1.0). The patient had a short arm cast for 4 weeks. The K-wires were removed 5 weeks postoperatively. We achieved good result clinically in 3, 9, and 36 months of follow up (Mayo Wrist Score of 70, 80, 90, respectively). The ROM of wrist is preferable than pre-surgery (RD 20o, UD 20o, and WF-WE 60o) with avascular necrosis of scaphoid in 9th month follow up (in 2019). Unfortunately, at 3 years of follow up, X-ray showed non-union scaphoid, avascular necrosis, and osteophytes between scaphoid and radius. Discussion: Unless it is asymptomatic, surgery is the recommended treatment for scaphoid non-union in order to limit further morbidity from pain, weakness, and stiffness of the wrist joint. However, in this case, the patient has been doing any activities with his right hand normally and never felt any pain in the last 2 years, eventhough the X-ray shows fracture line at distal of scaphoid. Thus, we choose not to do any treatment for it. Conclusion: In the case of trans-scaphoid lunate dislocation, the use of K-wire fixation shows excellent clinical outcome, but radiological finding shows non-union scaphoid with osteophytes, thus it has possibility to develop degenerative disease in the future. Keywords: Trans-scaphoid Lunate dislocation; Non-union; K-wire Fixation

Slight Elongation of the Scaphoid and Cancellous Bone Graft Without Compression for Treatment of Scaphoid Nonunions

In treating scaphoid nonunion, we have developed a technique of bone grafting and elongation of the scaphoid stabilizing the construct with K wires without compression. Bony union was achieved in the large majority of scaphoids as demonstrated on computed tomography (CT) scans. We advocate slight lengthening of the scaphoid with bone graft and K-wire fixation without compression of the grafted bone when treating scaphoid waist nonunion.

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.

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.

The effect of TLR-4 on the proliferation and differentiation of bone mesenchymal stem cells and its relationship with the Wnt signal transduction pathway during bone nonunion

Background

Bone nonunion is a special fracture complication that occurs in about 5% to 10% of cases. This type of fracture is difficult to heal, and causes great pain to patients and affects their quality of life. The mechanism of bone nonunion is not clear. In our study, we investigated the influence of Toll-like receptor (TLR)-3, TLR-4, and Wnt signaling pathways on the occurrence of bone nonunion.

Methods

Firstly, we established a Sprague Dawley (SD) rat model of femoral nonunion, and detected the expression levels of TLR-3, TLR-4, β-catenin, nemo-like kinase (NLK), c-Jun N-terminal kinase (JNK), and other proteins during model construction. For in vitro experiments, primary cultured bone mesenchymal stem cells (BMSCs) were divided into 4 groups: lipopolysaccharide (LPS, agonist of TLR-4) group, LPS + CLI095 (inhibitor of TLR-4) group, control group, and LPS + substance P (SP) group. The expression of β-catenin, NLK, JNK, and ALP and the osteogenic differentiation ability of cells were detected during culture.

Results

X-ray and hematoxylin and eosin (HE) staining results confirmed the successful modeling of bone nonunion. During the formation of the bone nonunion model, the expression of TLR-4 showed an upward trend. In vitro experiment results showed that inhibition of TLR-4 expression could enhance the proliferation and differentiation ability of BMSCs. The expression of β-catenin, the core protein of the canonical Wnt signaling pathway, increased rapidly in the first 2 weeks of bone nonunion construction, and decreased after 2 weeks. Non-canonical Wnt signaling pathway proteins NLK and JNK had no change in the first 2 weeks, and showed an upward trend after 2 weeks. In vitro experiment results showed that the expression of β-catenin was dominant in BMSCs with strong proliferation and differentiation ability, while the expression of NLK and JNK was dominant in BMSCs with weak proliferation and differentiation ability. These results suggest that the Wnt signaling pathway may regulate the occurrence of bone nonunion.

Conclusions

TLR-4 inhibits the proliferation and differentiation of BMSCs, and the transformation of the canonical Wnt signaling pathway to the non-canonical Wnt signaling pathway may lead to bone nonunion. Our study may provide new insights into the treatment of bone nonunion.

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.

Vascularized pisiform graft for the treatment of scaphoid nonunion: An anatomical study

Scaphoid fracture can evolve into scaphoid nonunion leading to wrist arthritis. Vascularized bone flaps used to treat scaphoid nonunion are supplied by delicate, small, or short arteries that are not always reliable. The pisiform bone has never been considered as a possible treatment of scaphoid nonunion since the traditionally harvested pedicle is too short. This study aimed to characterize the vascularization of the pisiform with the goal of developing a method of harvesting it with a longer pedicle that can be used as a graft to treat scaphoid nonunion. A cadaver study on 30 upper limbs was done in two parts: firstly, we dissected 20 cadaver specimens and documented the pisiform's vascularization (size, length, and articular surface) as well as anatomical characteristics of the dorsal ulnar artery; secondly, we used 10 cadaver specimens to study an experimental surgical procedure in which a vascularized pisiform graft is used to treat an artificially created nonunion and confirm its feasibility. The pisiform artery originated from the dorsal ulnar artery in all 20 dissections. Its average length of 4.036cm could be increased by 11% by ligating the upstream collateral branches from the dorsal ulnar artery. The pedicled vascularized pisiform flap was grafted to the scaphoid in 10 experimental procedures performed on fresh cadavers. The vascularized pisiform graft consists of a reliable vascular pedicle and well vascularized multi-cortical bone with a cartilaginous surface. However, more studies are needed to confirm the feasibility of this flap as an alternative for treating unstable scaphoid nonunion.

Wrist function recovery course in patients with scaphoid nonunion treated with combined volar bone grafting and a dorsal antegrade headless screw

Background

Surgical treatment is necessary for scaphoid nonunion. Open surgery with a combined volar and dorsal approach is thought to have poor functional outcomes and a prolonged recovery course. However, the detailed recovery course for this approach is rarely reported. The aim of this study was to investigate the recovery course and radiographic outcome for patients with scaphoid nonunion who underwent a combined volar bone grafting and dorsal antegrade headless screw approach.

Material and methods

Eighteen patients with scaphoid nonunion who underwent combined volar bone grafting and dorsal antegrade headless screw fixation were enrolled in this retrospective study. Preoperative and serial postoperative wrist functional and radiographic outcomes were collected and analysed.

Results

All 18 patients achieved bone union at a mean time of 14.3 weeks. Compared to the preoperative status, the grip strength, wrist motion arc, and Mayo Wrist score were improved significantly 6 months after surgery, whilst the Disabilities of the Arm, Shoulder, and Hand (DASH) score did not recover until 12 months after surgery. Significant improvements were found in all scaphoid radiographic parameters.

Conclusion

The surgical outcomes for scaphoid nonunion treated with a combined volar bone grafting and dorsal antegrade headless screw achieved a high union rate, with great wrist functional and radiographic outcomes. The earliest recovered wrist functional parameters were grip strength, motion arc, Mayo Wrist score and finally the DASH score at postoperative 6 months and 12 months, respectively.

[Nitinol memory alloy two foot fixator with autologous cancellous bone grafting for old scaphoid fracture and nonunion]

Objective

To summarize the effectiveness of nitinol memory alloy two foot fixator with autologous cancellous bone grafting in treating old scaphoid fracture and nonunion.

Methods

Between January 2013 and January 2017, 11 patients of old scaphoid fracture and nonunion were treated with nitinol memory alloy two foot fixator and autologous cancellous bone grafting. All patients were male with an average age of 26.1 years (range, 18-42 years). The fractures were caused by sport in 3 cases, falling in 7 cases, and a crashing object in 1 case. The interval between injury and operation was 6-18 months (mean, 8.9 months). Postoperative outcome measures included operation time, fracture healing time, grip strength, range of motion (ROM) of flexion, extension, ulnar deviation, and radial deviation, Mayo score, visual analogue scale (VAS) score, and the Disabilities of the Arm, Shoulder, and Hand (DASH) score.

Results

The operation time was 35-63 minutes (mean, 48 minutes). All incisions had primary healing with no infection and loosening or breakage of internal fixator. All patients were followed up 12-30 months (mean, 20.7 months). X-ray films showed that fracture healing was achieved in all patients with an average time of 15 weeks (range, 12-25 weeks). All internal fixators were removed after 10-12 months of operation (mean, 11.2 months). At last follow-up, the grip strength, ROMs of flexion, ulnar deviation, and radial deviation were superior to those before operation ( P<0.05), no significant difference was found in ROM of extension between pre- and post-operation ( t=0.229, P=0.824). There were significant differences in above indexes between affected and normal sides ( P<0.05). At last follow-up, the Mayo, VAS, DASH scores were also significantly superior to those before operation ( P<0.05).

Conclusion

For the old scaphoid fracture and nonunion, Ni-Ti arched shape-memory alloy fixator and autologous cancellous bone grafting can obtain good effectiveness, which is an effective treatment.

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.