Does Anyone Need a Vascularized Graft?

Scaphoid Nonunions Treated with Nonvascularized Bone Grafting and Screw Fixation

Background  Vascularized bone grafting with screw fixation is currently considered the treatment of choice for scaphoid nonunions with avascular necrosis (AVN) of the proximal pole. A viable alternative to using vascularized bone grafts for scaphoid nonunions with AVN is nonvascularized bone grafting with screw fixation. Question  What are the functional outcomes of patients with scaphoid nonunions and associated proximal pole AVN who are treated with nonvascularized distal radius bone grafting and screw fixation? Patients and Methods  Eight scaphoid nonunions with AVN, which received nonvascularized distal radius bone graft and screw fixation, underwent a retrospective review. Range of motion, strength, and Disabilities of the Arm, Shoulder, and Hand (DASH) scores were obtained. Follow-up X-rays were compared with immediate postoperative X-rays. Results  At a mean follow-up of 88.9 months, thumb palmar abduction and radial abduction were significantly higher on the operative side ( p  = 0.28 and 0.49, respectively). Extension/flexion arc was significantly lower in the operative wrist ( p  = 0.148). There was no significant difference between the operative and nonoperative sides with regard to strength. The median postoperative DASH score was 2.9 (interquartile range [IQR]: 8.3). There was no progression of osteoarthritis when immediate postoperative and follow-up X-rays were compared. Radiographic union was observed in six of the seven (85.7%) patients who were able to return to the office for follow-up radiographs. The mean scapholunate and radioscaphoid angles measured on X-rays were within normal anatomic range postoperatively. Conclusions  Using nonvascularized distal radius bone graft and screw fixation in the treatment of scaphoid nonunions with associated AVN has favorable radiologic and functional outcomes and should be considered a viable treatment option for this difficult problem.

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.

Decellularization of Massive Bone Allografts By Perfusion: A New Protocol for Tissue Engineering

In terms of large bone defect reconstructions, massive bone allografts may sometimes be the only solution. However, they are still burdened with a high postoperative complication rate. Our hypothesis is that the immunogenicity of residual cells in the graft is involved in this issue. Decellularization by perfusion might therefore be the answer to process and create more biologically effective massive bone allografts. Seventy-two porcine bones were used to characterize the efficiency of our sodium hydroxide-based decellularization protocol. A sequence of solvent perfusion through each nutrient artery was set up to ensure the complete decellularization of whole long bones. Qualitative (histology and immunohistochemistry [IHC]) and quantitative (fluoroscopic absorbance and enzyme-linked immunosorbent assay) evaluations were performed to assess the decellularization and the preservation of the extracellular matrix in the bone grafts. Cytotoxicity and compatibility were also tested. Comparatively to nontreated bones, our experiments showed a very high decellularization quality, demonstrating that perfusion is mandatory to achieve an entire decellularization. Moreover, results showed a good preservation of the bone composition and microarchitecture, Haversian systems and vascular network included. This protocol reduces the human leukocyte antigen antigenic load of the graft by >50%. The majority of measured growth factors is still present in the same amount in the decellularized bones compared to the nontreated bones. Histology and IHC show that the bones were cell compatible, noncytotoxic, and capable of inducing osteoblastic differentiation of mesenchymal stem cells. Our decellularization/perfusion protocol allowed to create decellularized long bone graft models, thanks to their inner vascular network, ready for in vivo implantation or to be further used as seeding matrices.

Rethinking Scaphoid Fixation

Scaphoid fixation, whether for acute injuries or nonunion, is made challenging by the small and intra-articular nature of the most commonly fractured carpal bone. The purpose of this article is to review the techniques to simplify scaphoid fixation and to optimize healing and early return to activity.

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.

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

Background

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

Methods

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

Results

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

Conclusions

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

Scaphoid Nonunion: A Review of Surgical Strategies

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

Vascularized Bone Grafting in the Treatment of Scaphoid Nonunion: A Clinical and Functional Outcome Study

Background  A malreduction or missed scaphoid fracture may lead to nonunion or avascular necrosis (AVN). The aim of this study was to analyze the radiological and clinical outcome of patients with scaphoid nonunion (SN), who were treated with 1,2-intercompartmental supraretinacular artery pedicled vascularized bone graft (1,2-ICSRA-VBG) fixed with K-wires or screws between 2014 and 2018. Methods  Radiological assessment included posteroanterior, lateral, oblique, and angled posteroanterior projection. The wrist active joint range of motion was assessed with a universal goniometer, and grip and pinch strength with a dynamometer. The disabilities of the arm, shoulder and hand (DASH) questionnaire was used to evaluate functionality. Statistical analysis was performed using SPSS software (v16.0). Results  A total of 68 patients (65 male) with a mean age 29.7 ± 8.5 years were evaluated in the study, and union was achieved in 55 (81%). A total of 45 (66%) patients had scaphoid waist fracture and 48 (71%) had AVN. Fixation was achieved with K-wires in 48 of the patients, and with screw in 20. The mean length of follow-up was 31.6 ± 14.6 (12-72) months. The mean radioulnar range of motion and DASH scores improved significantly after treatment ( p  < 0.001, p ≤ 0.001). Conclusions  The findings of this study showed that scaphoid unions can be treated successfully with high rates of union using the 1,2-ICSRA-VBG. This surgical technique requires special surgical experience. The functional outcome of patients improved after treatment, although smoking was found to be an important factor affecting functional results.

Scaphoid Nonunion Vascularized Bone Grafting in 2021: Is Avascular Necrosis the Sole Determinant?

The decision regarding the use of vascularized bone grafting (VBG) or nonvascularized bone grafting for the treatment of scaphoid nonunion (SNU) needs guidelines based on patient- and fracture-specific risk factors. Historically, the presence of avascular necrosis was viewed as the primary indication for VBG; however, avascular necrosis is not the only indicator to determine whether VBG can improve our treatment of difficult SNU cases. The methods of detecting scaphoid avascular necrosis lack consensus and accuracy, limiting their use as decision-making tools. Additionally, many other preoperative risk factors for SNU surgery failure have been reported and require careful and standardized study, including the location of nonunion in the scaphoid proximal pole, the duration of nonunion, previous failed nonunion surgery, smoking, and fracture nonunion displacement or collapse. An appropriate study size and design are needed to determine the factors that guide the use of VBG or nonvascularized bone grafting to optimize the outcomes of SNU surgery.

Predictors of Failure for Vascularized and Nonvascularized Bone Grafting of Scaphoid Nonunions: A Systematic Review

Objective This article compares predictors of failure for vascularized (VBG) and nonvascularized bone grafting (NVBG) of scaphoid nonunions.

Methods We conducted a systematic literature review of outcomes after VBG and NVBG of scaphoid nonunion. Fifty-one VBG studies (N = 1,419 patients) and 81 NVBG studies (N = 3,019 patients) met the inclusion criteria. Data were collected on surgical technique, type of fixation, time from injury to surgery, fracture location, abnormal carpal posture (humpback deformity and/or dorsal intercalated segmental instability [DISI]), radiographic parameters of carpal alignment, prior failed surgery, smoking status, and avascular necrosis (AVN) as defined by punctate bleeding, magnetic resonance imaging (MRI) with contrast, MRI without contrast, X-ray, and histology. Meta-analysis of proportions was conducted with Freeman–Tukey double arcsine transformation. Multilevel mixed-effects analyses were performed with univariable and multivariable Poisson regression to identify confounders and evaluate predictors of failure.

Results The pooled failure incidence effect size was comparable between VBG and NVBG (0.09 [95% confidence interval [CI] 0.05–0.13] and 0.08 [95% CI 0.06–0.11], respectively). Humpback deformity and/or DISI (incidence-rate radios [IRRs] 1.57, CI: 1.04–2.36) and lateral intrascaphoid angle (IRR 1.21, CI: 1.08–1.37) were significantly associated with an increased VBG failure incidence. Time from injury to surgery (IRR 1.09, CI: 1.06–1.12) and height-to-length (H/L) ratio (IRR 53.98, CI: 1.16–2,504.24) were significantly associated with an increased NVBG failure incidence, though H/L ratio demonstrated a wide CI. Decreased proximal fragment contrast uptake on MRI was a statistically significant predictor of increased failure incidence for both VBG (IRR 2.03 CI: 1.13–3.66) and NVBG (IRR 1.39, CI: 1.16–1.66). Punctate bleeding or radiographic AVN, scapholunate angle, radiolunate angle, and prior failed surgery were not associated with failure incidence for either bone graft type (p > 0.05).

Conclusion Humpback deformity and/or DISI and increasing lateral intrascaphoid angle may be predictors of VBG failure. Time from injury to surgery may be a predictor of NVBG failure. AVN as defined by decreased contrast uptake on MRI may be a marker of increased failure risk for both bone graft types.

Pedicled vascularized versus non-vascularized bone grafts in the treatment of scaphoid non-union: a meta-analysis of comparative studies

BACKGROUND

Whether pedicled vascularized bone grafts (PVBGs) are beneficial over non-vascularized bone grafts (NVBGs) still remains controversial. The aim of this study was to compare the clinical results of PVBGs and NVBGs for the treatment of scaphoid non-union.

METHODS

We conducted a meta-analysis of the published studies comparing outcomes of these two different surgical techniques for scaphoid non-union. Outcomes of union rate, time to union, functional results and re-operation rate were analysed.

RESULTS

Seven studies including four randomized controlled studies and three retrospective comparative studies with 413 participants were identified fitting inclusion criteria. Meta-analysis showed that (i) union rate in PVBG groups was 1.13 times of NVBG groups (P = 0.002); (ii) the PVBG groups reached bone union significantly earlier by 1.73 weeks (P < 0.01); (iii) there was no significant difference in functional results, including active range of motion, grip strength, Mayo Wrist Score and excellent and good rate (P > 0.05); and (iv) re-operation rate was similar between the two groups (P = 0.65).

CONCLUSIONS

Although the PVBG technique attains higher union rate and earlier union, this radiological advantage does not bring any functional benefits. In addition, PVBGs are of greater technical difficulty and need more operation requirements. Hence, clinicians should be cautious in electing PVBGs for treating scaphoid non-union.

A vascularized bone graft harvested from the dorsal base of the third metacarpal bone for the treatment of scaphoid nonunion

The purpose of this retrospective study was to introduce the use of an alternative vascularized bone graft for treating scaphoid non-union. The vascularized bone graft was harvested from the dorsal base of the third metacarpal bone. From May 2014 to September 2017, 29 patients with scaphoid non-union were treated. Grip and pinch strengths were compared to the contralateral side. The patients rated wrist joint pain on a visual analogue scale. Wrist function was assessed on Mayo Wrist Score. p < 0.05 was considered statistically significant. 18 scaphoids healed at 6 weeks and the other 11 at 16 weeks. Follow-up ranged from 28 to 73 months, for a mean 48 months. At final follow-up, mean wrist flexion had improved from 65° (range, 51°-81°) preoperatively to 72° (range, 61-78°) (p > 0.05), for a contralateral value of 74° (range, 65°-86°). Mean extension had improved from 56° (range, 44°-72°) to 60° (range, 47°-76°) (p > 0.05) for a contralateral value of 66° (range, 52°-80°). Mean wrist pain improved from 4 (range, 3-8) to 2 (range, 0-4) (p < 0.05). Mean pinch strength improved from 6.4 kg (range, 5.2-7.3 kg) to 8.6 kg (6.1-9.9 kg) (p < 0.05). Mayo Wrist Score improved from 49 (range, 10-65) to 92 (range, 70-100) (p < 0.05). Transferring a vascularized bone graft harvested from the base of the third metacarpal bone was an effective alternative for the treatment of scaphoid non-union, achieving bone healing and normal wrist function without significant donor-site morbidity. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

1,2 Intercompartmental Supraretinacular Artery-Based Vascularized Graft for Scaphoid Nonunion With Avascular Necrosis

Background The treatment for scaphoid nonunion with avascular necrosis is vascularized and non-vascularized bone grafts. A vascularized bone graft promotes biological healing and revascularizes ischemic bone. The purpose of this retrospective study is to analyze the outcome of 1,2 intercompartmental supraretinacular artery (1,2-ICSRA)-based vascularized graft in scaphoid nonunion with avascular necrosis. Materials and methods We treated 11 patients with scaphoid nonunion with avascular necrosis using a (1,2-ICSRA)-based vascular graft and Herbert screw fixation between 2013 and 2017. Plain radiographs, computed tomography (CT) scan, magnetic resonance imaging (MRI) confirmed the avascular necrosis in all patients. We noted the age, delay in treatment, time for bone union, preoperative range of movements, grip strength, scapholunate, intrascaphoid angle, and radiolunate angles. We confirmed the bone union by CT scan and measured the functional outcome with pain score, modified Mayo wrist score, grip strength, range of movement, and Disabilities of the Arm, Shoulder, and Hand (DASH) score. Results The mean age of the patients was 29 years (range 20-42 years). The mean follow-up was 31 months (range, 26-36 months). All patients achieved good radiological union and revascularization of the proximal pole necrosis at an average of 14 weeks (range, 12-18 weeks). There was a significant postoperative improvement in grip strength, visual analog scale VAS score, intrascaphoid angle, scapholunate angle, and radiolunate angle (p<.05). The mean range of wrist flexion was 88%, extension 70%, radial deviation 80%, and ulnar deviation 85% of the opposite side. Conclusions Scaphoid nonunion with avascular necrosis can be treated with a 1,2-ICSRA-based vascularized bone graft. Vascularized bone grafts promote biological healing and revascularization of the ischemic bone.

[Scaphoid non-union: Experience from more than 280 reconstructions using a medial femur condyle bone graft]

BACKGROUND

Since 2008 we have been using many free vascularized medial femoral condyle grafts for reconstruction of difficult scaphoid non-unions. This article aims to report our results and experiences.

PATIENTS AND METHODS

Until the end of 2019 a total of 287 patients had a microvascular scaphoid reconstruction, 158 with use of a corticocancellous, and 129 using an osseocartilaginous graft. Complete analysis of all of these patients was impossible. This manuscript is based on a retrospective analysis of 28 out of 42 patients with corticocancellous grafts operated on between 2008 and 2010 with a mean follow-up time of 6.1 years as well as another 44 out of 76 patients with an osseocartilaginous graft operated on between 2011 and 2016 with a mean follow-up time of 44 months. Follow-up included clinical parameters, conventional x-rays, a DASH-Score and a modified Mayo wrist score. Additionally, the authors report their personal experiences - necessarily without quantification. In view of this incomplete data-pool statistical analysis was not reasonable.

RESULTS

In the group with corticocancellous reconstructions bony healing was achieved in 69 %, salvage operations were required in 9,5 %. The 28 patients had a mean DASH-Score of 11, a mean modified Mayo wrist score of 83 points, a mean ROM of 86° and a mean grip strength of 89 % of the contralateral side. In the group with osseocartilaginous reconstructions complete bony healing was seen in 80 %, partial healing in 5 %, and salvage procedures were required in 11 %. The remaining 39 patients had a mean DASH-Score of 15, a mean modified Mayo wrist score of 80 points, a mean ROM of 90° and a grip strength of 81 % of the contralateral hand. A specific complication was an ossification of the pedicle, but the main problem was a satisfying reconstruction of the shape of the scaphoid and reestablishment of carpal stability in far advanced cases. We could not identify factors reliable for the persisting non-unions.

CONCLUSIONS

These operations combine great chances for healing with considerable risks for serious complications. So future patients have to be fully informed, so that their decision for such a procedure is based on realistic expectations.

[Clinical and imaging methods in diagnostics of scaphoid fracture and non-union]

Clinical and radiological diagnostics are the base of a differentiated treatment of carpal disorders. With special regard to diagnostics of the scaphoid, not only the choice and the correct implementation of the imaging methods are crucial, but also their methodical limitations have to be taken into account. No other common fracture is more often undiagnosed, because neglected or overlooked. Concomitantly, delayed or untreated scaphoid fractures require demanding therapies in the sequel and may lead to functional restrictions in the long-term. This review article aims to discuss the clinical and imaging diagnostics for scaphoid fractures and non-union.

Clinical and radiological results of the vascularized medial femoral condyle graft for scaphoid non-union

INTRODUCTION

This study evaluated the use of a free vascularized bone graft with and without cartilage from the medial femoral condyle (MFC) in patients with recalcitrant scaphoid non-union, with a special focus on union rates and the osteochondral graft for proximal pole destruction.

MATERIALS AND METHODS

Thirty-eight avascular scaphoid non-unions in 37 patients who were treated with a free osteoperiosteal or osteochondral MFC graft were retrospectively evaluated (mean follow-up 16 months). Bone union, the scapholunate and the radiolunate angles were evaluated on X-ray images. The range of motion, grip strength, VAS, DASH and PRWE scores were evaluated clinically.

RESULTS

The overall union rate was 95%. Bone union was achieved in 27 out of 29 (93%) scaphoids treated with a free osteoperiosteal MFC grafts and in 9 out of 9 (100%) scaphoids treated with a free osteochondral MFC graft. The range of motion remained almost unchanged, while grip strength increased significantly (34 kg vs. 44 kg) and the VAS (22-5), DASH (59-19) and PRWE (62-30) score decreased significantly. The scapholunate (71°-65°) and radiolunate (28°-18°) angle decreased. No major donor site morbidity was observed. Postoperative complications were observed in eight cases (21%).

CONCLUSIONS

The vascularized medial femoral bone graft leads to a good functional outcome in the treatment of scaphoid non-unions. The graft provides adequate blood supply and structural stability to the scaphoid. A proximal pole destruction can be replaced using an osteochondral graft with promising short-term results preventing carpal osteoarthritis and collapse.

Decellularized Extracellular Matrix as a Potent Natural Biomaterial for Regenerative Medicine

Decellularization technique is a favorable method used to fabricate natural and tissue-like scaffolds. This technique is important because of its remarkable ability to perfectly mimic the natural extracellular matrix (ECM). ECM-based scaffolds/hydrogels provide structural support for cell differentiation and maturation. Therefore, novel natural-based bioinks, ECM-based hydrogels, and particulate forms of the ECM provide promising strategies for whole organ regeneration. Despite its efficacious characteristics, removal of residual detergent and the presence of various protocols make this technique challenging for scientists and regenerative medicine-related programs. This chapter reviews the most effective physical, chemical, and enzymatic protocols used to remove the cellular components and their challenges. We discuss the applications of decellularized ECM (dECM) in tissue engineering and regenerative medicine with an emphasis on hard tissues.