Unstable scaphoid fracture nonunion: a medium-term study of anterior wedge grafting procedures

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.

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.

The Author's Technique for the Management of Unstable Scaphoid Nonunions: Tips and Tricks

This article presents historical aspects, rationale, indications, planning, and execution of anterior interpositional bone grafting technique for unstable scaphoid nonunions. The author's original technique considers four points: (1) preoperative planning based on comparative anteroposterior radiographs in maximal ulnar deviation was used to calculate resection zone, size of the graft, and scaphoid length; (2) a volar approach was used; (3) an iliac crest wedge-shaped corticocancellous graft was interposed; and (4) Kirschner wires were inserted for fixation. Contemporary refinements of the technique including a modification to treat nonunions with failed previous screw fixation with tricks and hints and results are shown.

Scapho-Capitate Ratio for Estimation of Scaphoid Length

Background: The failure of scaphoid reconstruction by restoring both length and shape may lead to carpal mal-alignment and progressive degenerative arthritis. The aim of our study is to find a reliable method to find out the scaphoid length without measuring the contralateral scaphoid. Methods: Three X-ray wrist views were collected for 51 patients without any signs suggesting any hand and wrist fractures. The scaphoid, capitate and 3^rd metacarpal bone axes lengths and carpal height were measured by 4 hand surgeons separately. Results: The scapho-capitate ratio was 1.1 ± 0.084, 1.01 ± 0.084 and 0.92 ± 0.109 for lateral, postero-anterior with ulnar deviation and postero-anterior view respectively. The ulnar deviation view had the highest reliability. Conclusions: Scapho-capitate ratio estimation is an easy and accurate measure of normal scaphoid length in situations when the scaphoid is short. It is helpful for the estimation of the size of the bone graft that need for reconstruction of the scaphoid.

Overstuffing of Unstable Scaphoid Nonunions: A Radiographic Analysis of Carpal Parameters

PURPOSE

The purpose of this study was to radiographically evaluate scaphoid length and carpal parameters before and after reconstruction of nonunions with interposition vascularized medial femoral condyle (MFC) bone graft to determine if the scaphoid was overstuffed or if normal anatomy was restored and to determine the effect on ulnar carpal translocation when the volar radiocarpal ligaments were left unrepaired.

METHODS

Thirty-nine patients with established scaphoid nonunions with carpal collapse were reconstructed by interposition vascularized MFC bone grafts without repair of the volar radiocarpal ligaments. Pre- and postoperative radiographs and computed tomography scans of the 39 patients were reviewed. The scaphoid length, capitate-ulnar distance ratio (CUDR), modified carpal height ratio (MCHR), radiolunate (RL) and scapholunate (SL) angles were measured before and 3 months after surgery. Thirteen of these patients had contralateral wrist radiographs that were used for analysis of scaphoid length restoration.

RESULTS

No significant changes were observed for CUDR and MCHR before and after surgery. The length of the scaphoid significantly improved after reconstruction from 21.9 ± 3.3 to 23.7 ± 3.4 mm on posteroanterior x-ray views and from 24.0 ± 2.2 to 27.7 ± 2.8 mm on lateral views. The RL and SL angles also changed significantly after surgery from 19.5° ± 13.5° to 4.1° ± 16.9° and from 67.5° ± 12.5° to 56.0° ± 12.5°, respectively. Regarding the 13 patients with contralateral x-rays, no differences were seen on CUDR, MCHR, or scaphoid length on posteroanterior x-ray views. However, the scaphoid length on lateral x-ray views increased from 23.1 ± 2.40 to 27.6 ± 2.78 mm and was significantly longer than the contralateral side by 9.6%. The RL and SL angles were restored and comparable with the contralateral side.

CONCLUSIONS

The use of vascularized MFC bone graft increased scaphoid length by 9.6% and restored normal carpal alignment. Despite the increased scaphoid length compared with the contralateral side, the lack of repair of the volar radiocarpal ligaments did not cause ulnar carpal translocation in short-term follow-up.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

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.

Editorial Commentary: The Practical Goal of Arthroscopic Osteosynthesis for the Treatment of Unstable Scaphoid Nonunion

Arthroscopic reduction with osteosynthesis using bone grafting has become a successful alternative to open techniques for the treatment of chronically unstable scaphoid nonunions. Several studies have demonstrated that arthroscopic techniques are safe and reproducible in addition to causing less soft tissue damage and providing promising short- and mid-term results. However, these techniques have limitations in restoring normal carpal alignment, especially in patients with unstable scaphoid nonunion and carpal collapse deformities, although this does not affect the recovery of clinical function. Therefore, the practical goal of arthroscopic technique should be kept in mind when treating unstable scaphoid nonunions.

Retrospective Comparative Outcomes Analysis of Arthroscopic Versus Open Bone Graft and Fixation for Unstable Scaphoid Nonunions

PURPOSE

To compare union rates and clinical and radiologic outcomes after arthroscopic and open bone grafting and internal fixation for unstable scaphoid nonunions.

METHODS

Between March 2009 and November 2014, patients with unstable scaphoid nonunion underwent arthroscopic (group A) or open (group O) bone grafting and internal fixation. One senior surgeon alternatively performed either arthroscopic or open osteosynthesis for the same surgical indications. Visual analog scale score, grip strength, active range of motion, Mayo wrist score (MWS), and Disabilities of Arm, Shoulder, and Hand score were assessed preoperatively and postoperatively. Union was determined by computed tomography 8 to 10 weeks postoperatively with bridging trabecula at the nonunion site. Scapholunate angle (SLA), radiolunate angle (RLA), and lateral intrascaphoid angle (LISA), plus height/length ratio (HLR) served to gauge carpal bone alignment in preoperative and postoperative radiographs. Those outcomes of patients with carpal collapse deformities, who met following conditions; (1) LISA of >45° or HLR of >0.65 on computed tomography images or (2) SLA of >60° or RLA of >10° on plain radiographs, were also compared.

RESULTS

Overall, 62 patients qualified for study (group A, 28; group O, 34). Union rates did not differ by patient subset (group A, 96.4%; group O, 97.1%; P ≒ 1); and visual analog scale score, grip strength, range of motion, Mayo Wrist Score, and Disabilities of Arm, Shoulder, and Hand scores were similar at last follow-up. In radiographic assessments, SLA, RLA, and LISA were similar, whereas scaphoid HLR excelled through open technique (group A, 0.59 ± 0.07; group O, 0.55 ± 0.05; P = .002). Subgroup analysis of patients with carpal collapse deformities (group A, 9; group O, 14) showed that all radiographic measures in group A (vs group O) reflected lesser correction (SLA, 56.7° ± 7.3° vs 49.2°±9.1° [P = .049]; RLA, 9.2° ± 2.0° vs 5.7° ± 3.0° [P = .005]; LISA, 34.8° ± 4.8° vs 25.6° ± 13.0° [P = .028]; HLR, 0.66 ± 0.04 vs 0.54 ± 0.07 [P < .001]).

CONCLUSIONS

Arthroscopic and open bone grafting and internal fixation in treating unstable scaphoid nonunions, did not show any significant differences in clinical and radiologic outcomes at the minimum of 2 years after operation. In scaphoid nonunions with carpal collapse deformities, open bone grafting restored better carpal alignment than arthroscopic bone grafting, although there were no differences in clinical outcomes between the 2 techniques.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Cylinder-Shaped Bone Graft for Scaphoid Nonunion

BACKGROUND

Wedge-shaped bone grafts that are internally fixed by a Herbert-type screw are a well-established surgical treatment for scaphoid nonunion. A procedure using cylinder-shaped bone grafts was also reported, but preoperative wrist functions were not assessed. In addition, it was not reported whether the humpback deformity of the scaphoid nonunion was corrected. The purpose of the current study was to compare preoperative wrist functions in cases of scaphoid nonunion with those observed at final follow-up, using cylinder-shaped bone grafts The humpback deformity of the scaphoid nonunion was also evaluated.

METHODS

We conducted a retrospective study to examine operative outcomes from 2008 to 2015. Twelve wrists in 12 patients (average age, 41 years; range, 17-67), with a mean follow-up of 19 months, were included in the current study. Cylinder-shaped bone grafts were obtained from the iliac crest with a newly designed trephine and fixed with a Herbert-type screw. We reviewed both the preoperative wrist functions and those obtained at final follow-up.

RESULTS

Union was achieved in 11 of 12 nonunion cases. Preoperative wrist functions, except for the range of wrist motion, significantly improved by final follow-up.

CONCLUSIONS

We conclude that the use of cylinder-shaped bone grafts improves preoperative wrist functions in cases of scaphoid nonunion.

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

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

Treatment of the scaphoid humpback deformity - is correction of the dorsal intercalated segment instability deformity critical?

Treatment of scaphoid fractures has been focused mainly on achieving union, with less attention to restoring normal scaphoid shape and orientation. Malalignment of one carpal bone will disrupt the kinetics of the entire wrist. The dorsal intercalated segment instability deformity associated with scaphoid waist nonunion is a nondissociative form of carpal instability. It has to be reduced in the treatment of scaphoid waist nonunions to avoid kinetic problems that will lead to arthritic changes. Computerized tomography scanning has become indispensable to visualize the humpback deformity clearly. Different techniques may be used to restore the normal anatomy of scaphoid, from non-vascularized graft to arthroscopic bone grafting, and also the option of vascularized bone grafting.

Arthroscopic reconstruction for unstable scaphoid non-union

OBJECTIVE

To evaluate the results of arthroscopic reconstruction for the treatment of unstable scaphoid non-union with cancellous bone autograft.

METHODS

13 patients were treated with a mean age of 26 (18-45) years. The average time from injury until surgery was 14 (6-48) months. Preoperative and postoperative clinical and radiological parameters were evaluated. Mean follow-up was 16.8 (12-36) months.

RESULTS

Consolidation was achieved in all cases at 7 (4-10 weeks), no patient had complications or reoperations. Range of motion, pain, functional assessment (DASH questionnaire) and radiological measurements improved compared to preoperative measurements. The average range of flexion improved: flexion 71.9° (55°-80°) to 81.7° (55°-90°), extension 66.3° (30°-80°) to 84.4° (70° -90°), ulnar deviation 21.5 (10°-25°) to 25.5° (20°-45°) and radial deviation 11.9° (5°-25°) to 13.3° (10th-20th). Pain (VAS 0-10) improved from 6.8 (4-10) to 0.7 (0-3). DASH functional scale improved from 36 (12-78) to 8 (0-10). The Scapho-Lunate Angle improved from 67.7° (62°-88°) to 47° (32°-55°), and the Radio-Lunate Angle improved from 30.8° (10° -45°) to 4(0°-10°).

CONCLUSION

Treatment of unstable scaphoid non-union with cancellous bone graft assisted by arthroscopy presents good clinical results with a short period of consolidation and recovery.

Clinical outcome after alternative treatment of scaphoid fractures and nonunions

PURPOSE

Achieving stable fixation of scaphoid fractures and nonunions continues to be a challenge. Compression screw fixation has been the current standard surgical procedure. However, in some cases, bone healing cannot be achieved and requires further revision. Recent series reintroduced volar plating as valid option for stable fixation. The aim of the study was to review clinical outcome of alternative scaphoid treatment.

METHODS

From 2011 to 2014, nine patients with scaphoid fracture were treated by Headless Compression Screw (HCS) and seven patients with scaphoid nonunion by HCS or volar mini condylar plate with bone graft. The average age was 34.4 years and the average time to follow-up was 19.3 months. From 1996 to 1998, 38 patients with scaphoid nonunion were treated using compression screw (S-group) or volar mini condylar plate (P-group) with bone graft. The average age was 39.6 years and the average time to follow-up was 26.2 months.

RESULTS

The union rate was 100%. For scaphoid fractures, the mean Modified Mayo Wrist Score (MMWS) was 94.1 and the DASH score 7.4. From 2011 to 2014, the MMWS was 87.9 and the DASH score 7 in scaphoid nonunions. In the period between 1996 and 1998, the MMWS was 67.2 in the P-group and 58.6 in the S-group, and the DASH score 16.8 and 28.2.

CONCLUSIONS

Our study demonstrated that appropriate application of the HCS was able to produce very satisfactory results in scaphoid fractures and nonunions. In our opinion, however, the method of scaphoid plate osteosynthesis can achieve a higher degree of stability, particularly rotational stability, in case of multifragmentary avascular scaphoid nonunions.

Vascularized versus non-vascularized bone grafts in the treatment of scaphoid non-union

INTRODUCTION

Conventional non-vascularized bone grafts as well as vascularized bone grafts are used to treat scaphoid non-union (SN). Due to limited available studies, the field of application using both grafts for SN still remains controversial. The aim of this study was to evaluate a treatment algorithm for the use of both vascularized versus non-vascularized bone grafts based on clinical outcomes and quality of life (QoL) to improve the level of evidence.

MATERIALS AND METHODS

Based on a retrospective cohort study, including 28 patients with vascularized and 45 patients with conventional bone grafts, functional parameters, radiological outcome, Mayo-wrist-score, and QoL by SF-36 were applied to statistically compare the outcome of these two techniques.

RESULTS

Time between last procedure or trauma and study group scaphoid reconstruction was almost double in the vascularized bone grafting group. Comparable union rates were achieved with vascularized as well as non-vascularized bone grafts. Significant differences were observed between both groups for grip strength and radial-ulnar active range of motion. Further functional outcomes, radiological outcomes as well as QoL were found similar for both techniques in patients with surgical union.

DISCUSSION AND CONCLUSIONS

In order to achieve comparable and appropriate treatment results, vascularized bone grafts are recommended for patients with delayed treatment, impaired scaphoid vascularity, and revision surgery. Even in preselected, complex cases, the results are comparable to conventional grafts, which are the basis for further patient education and approve the powerful role of surgical angiogenesis of vascularized bone grafts.

Ilizarov fixation for the treatment of scaphoid nonunion: a novel approach

OBJECTIVES

To evaluate the safety and efficacy of the Ilizarov fine-wire compression/distraction technique in the treatment of scaphoid nonunion (SNU), without the use of bone graft.

DESIGN

This is a prospective study of 20 consecutive patients in one center.

PATIENTS AND METHODS

This study included 20 patients (19 males) with a mean SNU duration of 14.5 months. Four patients had proximal pole, 15 had waist, and 1 had a distal SNU. Patients with carpal instability, humpback deformities, carpal collapse, avascular necrosis, and marked degenerative change were excluded. Following frame application, the treatment comprises three stages: The frame is distracted by 1 mm per day until the radiographs show a 2-3 mm opening at the SNU site (mean 10 days); the SNU site is compressed for 5 days, at a rate of 1 mm per day, with the wrist in 15 degrees of flexion and 15 degrees of radial deviation; the wrist is then immobilized in the Ilizarov fixator for 8 weeks.

RESULTS

Radiographic (radiography and CT scan) and clinical bony union was achieved in all 20 patients after a mean of 90.3 days (70-130 days). All patients returned to their pre-injury occupations. Thirteen patients had excellent results, four good, and three fair, according to the Mayo wrist score.

CONCLUSIONS

In these selected patients, this technique safely achieved bony union without the need to open the SNU site and without the requirement of bone graft.

Estimating Scaphoid Lengths Using Anatomical Measurements in the Wrist

PURPOSE

In reconstructive surgery of scaphoid nonunions with humpback deformity, some surgeons recommend restoration of the normal scaphoid length whereas others overexpand the normal length to ensure carpal realignment and prevent late collapse. To be able to define overexpansion and investigate which levels of overexpansion yield optimal clinical results, a precise method for estimating the original scaphoid length is required. The purpose of this anatomic study was to investigate the precision of estimating normal scaphoid lengths based on intact adjacent bone dimensions, compared with using the contralateral scaphoid length.

METHODS

From bilateral computed tomographic scans of 28 healthy wrist pairs, 3-dimensional virtual bone models were created. The left and right scaphoid lengths were determined at the central axis. The capitate length at the central axis and the distal radius width served to derive an ipsilateral scaphoid length estimate. Estimation precision for individual cases was based on the 95% range (±1.96 × SD) of the observed differences between the actual and estimated lengths.

RESULTS

On average, the capitate length was 10% smaller than the scaphoid length; the radius width was 9% larger. Consequently, we averaged the capitate length and radius width for ipsilateral estimations. The average difference between the scaphoid length and the latter ipsilateral estimate was 0.1 mm. The average contralateral scaphoid length difference was also 0.1 mm. Estimation precisions, however, were ±2.2 and ±1.4 mm, respectively.

CONCLUSIONS

Scaphoid length estimation based on the contralateral scaphoid is more precise than the estimating scaphoid length using the ipsilateral radius and capitate.

CLINICAL RELEVANCE

Scaphoid overexpansion can be ensured if the restored length is at least 1.4 mm longer than the contralateral length. This may be valuable information when establishing a target length for reconstruction and investigating the consequences of scaphoid overexpansion on clinical function, such as range of motion, which are currently unknown.

Scaphoid fracture non-union: a systematic review of surgical treatment using bone graft

This systematic review assesses the quality and outcomes of published articles concerning bone graft surgery for scaphoid fracture non-union. Searches of the CENTRAL, MEDLINE, EMBASE, CINAHL and AMED databases captured 2710 articles. Each article was screened and 144 met our inclusion criteria. Data regarding source, study design, population, intervention, comparator and outcomes were extracted. There were 5464 scaphoid non-union outcomes within the 144 studies. Mean reported union rates for vascularized and non-vascularized bone graft were 84% and 80%, respectively. Avascular necrosis was diagnosed in several ways and, when present, the vascularized bone graft union rate was 74% compared with 62% with non-vascularized bone graft. Reported union rates vary considerably. These differences may be due to patient factors, fracture factors, treatment factors or study design failures or bias. We recommend that future researchers take into account the deficiencies of previous studies and use the suggested minimum data set in future studies.

LEVEL OF EVIDENCE

II.

Is Arthroscopic Bone Graft and Fixation for Scaphoid Nonunions Effective?

BACKGROUND

Arthroscopic management of scaphoid nonunions has been advanced as a less invasive technique that allows evaluation of associated intrinsic and extrinsic ligamentous injuries; however, few studies have documented the effectiveness of arthroscopic treatment of scaphoid nonunions and which intraarticular pathologies coexist with scaphoid nonunions.

QUESTIONS/PURPOSES

(1) What are the outcomes of arthroscopic management of scaphoid nonunions as assessed by the proportion of patients achieving osseous union, visual analog scale (VAS) pain score, grip strength, range of motion, Mayo Wrist Score (MWS), and Disabilities of the Arm, Shoulder and Hand (DASH) score? (2) What complications are associated with arthroscopic scaphoid nonunion management? (3) What forms of intraarticular pathology are associated with scaphoid nonunions?

METHODS

Between 2008 and 2012, we treated 80 patients surgically for scaphoid nonunions. Of those, 45 (56%) had arthroscopic management. During that time, our general indications for using an arthroscopic approach over an open approach were symptomatic scaphoid nonunions without necrosis of the proximal fragment, severe deformities, or arthritis. Of the patients treated arthroscopically, 33 (73%) were available for followup at least 2 years later. There were five distal third, 19 middle third, and nine proximal third fractures. The mean followup was 33 months (range, 24-60 months). Union was determined by CT taken at 8 to 10 weeks after operation with bridging trabecula at nonunion site. VAS pain scores, grip strength, active flexion-extension angle, MWS, and DASH scores were obtained preoperatively and at each followup visit. The coexisting intraarticular pathologies and complications were also recorded.

RESULTS

Thirty-two (97%) scaphoid nonunions healed successfully. At the last followup, the mean VAS pain score decreased (preoperative: mean 4.5 [SD 1.8], postoperative: mean 0.6 [SD 0.8], mean difference: 3.9 [95% confidence interval {CI}, 3.2-4.6], p < 0.001) and the mean active flexion-extension angle increased (preoperative: mean 100° [SD 26], postoperative: mean 109° [SD 16], mean difference: 9° [95% CI, 2-16], p = 0.017). The mean grip strength increased (preoperative: mean 35 kg of force [SD 8], postoperative: mean 50 kg of force [SD 10], mean difference: 15 kg of force [95% CI, 11-19], p < 0.001). The mean MWS increased (preoperative: mean 56 [SD 23], postoperative: mean 89 [SD 8], mean difference: 33 [95% CI, 26-41], p < 0.001) and the mean DASH score decreased (preoperative: mean 25 [SD 18], postoperative: mean 4 [SD 3], mean difference: 21 [95% CI, 15-28], p < 0.001). There were no operation-related complications and no progression of arthritis at the last followup. Seventeen patients had coexisting intraarticular pathology, including nine triangular fibrocartilage complex tears (seven traumatic and two degenerative), 17 intrinsic ligament tears (nine scapholunate interosseous ligament tears and eight lunotriquetral interosseous ligament tears), and five mild radioscaphoid degenerative changes.

CONCLUSIONS

Arthroscopic management of scaphoid nonunions without severe deformities or arthritis was effective in this small series. Although intraarticular pathologies such as triangular fibrocartilage complex tears and intrinsic ligament injuries commonly coexisted with scaphoid nonunions, patients generally achieved good results.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

A central threadless shaft screw is better than a fully threaded variable pitch screw for unstable scaphoid nonunion: a biomechanical study

INTRODUCTION

An interpositional wedge bone graft is a procedure performed to restore carpal height and scaphoid length for displaced scaphoid nonunions with carpal instability. The purpose of this study was to investigate which headless screw design (threadless central shaft screw or fully threaded variable pitch compression screw) is biomechanically preferred when an interpositional bone graft is needed.

METHODS

A total of 24 cadaveric scaphoid interpositional bone grafts were divided into three groups and fixed with HCS 3.0, Herbert-Whipple or Acutrak mini-screws, and the relative biochemical stability of each was measured. The specimens were tested using an Instron tensile testing machine to calculate stiffness and load to failure. To measure compression forces at different interfragmentary gaps, 30 interpositional polyurethane bone graft models were generated with three pieces of cancellous sawbone block, and two custom-made load-cells were inserted in each gap. The models were then divided into three groups and fixed with the above screw types. The compression forces at different interfragmentary gaps were measured immediately and 30 min after screw fixation.

RESULTS

The average stiffness and load to failure were similar among the three groups (p>0.05). The average compression force measured at each interfragmentary gap was highest in the HCS 3.0 fixation group, followed by the Herbert-Whipple and Acutrak mini-screw fixation groups both immediately after screw fixation and after 30 min (at which time there were significant decreases in force). The compression forces measured at different interfragmentary gaps were almost identical in the HCS 3.0 and Herbert-Whipple screw fixation groups; however, the force measured at the leading side was significantly lower than that measured at the trailing side in the Acutrak mini-screw fixation group.

CONCLUSION

The threadless central shaft screw design is biomechanically preferred over the fully threaded variable pitch screw design because it achieves higher and identical compression forces at different interfragmentary gaps with similar stiffness and load to failure.

The effect of delayed treatment on clinical and radiological effects of anterior wedge grafting for non-union of scaphoid fractures

INTRODUCTION

The aim of the treatment of displaced scaphoid non-unions is the restoration of normal scaphoid anatomy. Restoration of normal scaphoid anatomy at an earlier stage might have functional benefits as maladaptive carpal ligament contractures and the development of preliminary osteoarthritis could be avoided. The purpose of this retrospective study was to determine if late reconstruction (delayed reconstruction group) was as effective as early reconstruction (early reconstruction group) of scaphoid non-union in restoring clinical and radiological outcome.

PATIENTS AND METHODS

The early reconstruction group included patients who underwent surgery between 6 and 12 months after the original fracture. This group consisted of 14 male and 2 female patients. The delayed reconstruction group included patients who underwent surgery 12 or more months after the original fracture. This group consisted of 9 male and 1 female patients. Average time from injury to surgery in the early reconstruction group was 10 months (range 6-12 months) and mean postoperative follow-up period averaged 58 months (range 19-72 months). Average time from injury to surgery in the delayed reconstruction group was 69 months (range 12-88 months) and mean postoperative follow-up period averaged 62 months (range 24-80 months). All patients showed a humpback deformity as well as a DISI deformity with the radiolunate angle being greater than 15°. The outcome was assessed on the basis of measurement of active wrist range of motion and grip power. Wrist pain was evaluated using a visual analogue scale. Functional subjective outcome was evaluated with the DASH and PRWE scores. Results were compared to preoperative measurements as well as to the uninjured contralateral side. Pre- and post-operative radiographs were assessed for scapholunate angle (SLA) as a measure of palmar rotation and radiolunate angle (RLA). The presence of DISI was defined by a difference of >60° for the SLA or of >10° for the RLA between the affected and unaffected wrist.

RESULTS

In the early reconstruction group bone union and correction of DISI deformity could be achieved for all patients (n = 16). In the delayed reconstruction group bone union could only be achieved without correction of the DISI deformity in six patients (60 %). In four patients (40 %) of the delayed reconstruction group non-union persisted. For the early reconstruction group at final follow-up mean flexion-extension arc, mean ulnar-radial-deviation arc and mean grip strength were 82, 91.5 and 82 % of uninjured side, respectively. Mean pain level decreased from 6 points before surgery to 1 point at final follow-up. The preoperative DASH changed from 48 to 17 and the preoperative PRWE changed from 30 to 14. The SLA changed from 51° to 48° and the RLA from 18° to 9°. Six patients from delayed reconstruction group showed bone union, but no correction of DISI deformity at final follow-up. Functional and radiological results showed only slight improvement. The remaining four patients from delayed reconstruction group with a persistent non-union continued to experience pain, reduced grip strength and limited range of wrist movement and DISI deformity persisted.

CONCLUSION

In conclusion, wedge-shaped bone grafting of scaphoid non-union leads to increased functional scores as well as to improved carpal angles as long as bony union can be achieved. Remaining non-union and the inability to correct DISI deformity are severely correlated with an increased time frame between fracture and surgical treatment. Furthermore, the vascularization of the proximal fragment and patients' smoking habits has to be taken into consideration preoperatively.

Vascularized bone grafting and distal radius osteotomy for scaphoid nonunion advanced collapse

PURPOSE

To determine the outcome of an alternative treatment for wrists with stages I to III scaphoid nonunion advanced collapse using a closing-wedge osteotomy of the distal radius and a vascularized bone graft for scaphoid reconstruction.

METHODS

Twelve patients with scaphoid nonunion advanced collapse (stage I, 3; stage II, 7; stage III, 2) treated with a vascularized bone graft interposition for the scaphoid and a closing-wedge osteotomy for the distal radius were retrospectively reviewed. Data were obtained and analyzed from the radiographs, and we assessed the pre- and postoperative range of motion, grip strength, visual analog scale pain score, as well as the Mayo and Disabilities of the Arm, Shoulder, and Hand (DASH) functional scores.

RESULTS

Follow-up ranged from 2 to 11 years. All scaphoid nonunions united after an average of 9 weeks, and all osteotomies united after an average of 8 weeks. Although there was radiographic progression of the scaphoid nonunion advanced collapse stage in 5 of 12 cases, there was major improvement in visual analog scale pain score (from 6.1 to 0.8) and in both Mayo (from 64 to 85) and DASH (from 40 to 9) functional scores. The range of motion remained unchanged, and grip strength trended toward minor improvement. The carpal height was preserved, and the dorsal intercalated segmental instability was corrected.

CONCLUSIONS

Scaphoid reconstruction with vascularized bone graft combined with closing-wedge distal radius osteotomy preserved wrist function for scaphoid nonunion advanced collapse. The method offers pain relief and does not compromise wrist motion or grip strength.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

[Results of surgical treatment of carpal scaphoid pseudarthrosis using the Fisk-Fernández technique]

AIM

The aim of the study was to evaluate the clinical and radiological results obtained in the treatment of carpal scaphoid non-union treated at the University Hospital of Valladolid using the Fisk Fernandez technique.

MATERIAL AND METHODS

A review was performed on 43 cases of surgically treated non-union using Fisk Fernandez technique with a minimum of 6 months follow-up. The time until surgery, previous treatment, the mechanism of injury, type of non-union, and the existence of radio-carpal arthrosis were evaluated. A subjective evaluation was performed using the "Scaphoid Score" and the DASH, plus an objective assessment with the modified Green & O'Brien, together with the measurement of the intra-scaphoid, radioulnar, scapholunate angles, and carpal height.

RESULTS

The median time to healing in the series was between 16 to 24 weeks, except in 3 patients who failed to heal and required salvage surgery. There was a statistically significant variation between the preoperative and postoperative angles and carpal height measured in the X-rays.

DISCUSSION

There are different osteosynthesis techniques and materials for the treatment of non-union. The evaluation of results performed using objective and subjective scales showed variable results between studies. Different techniques are aimed at preventing the progression of the disease.

CONCLUSION

The Fisk Fernandez technique enables the deformity of the scaphoid to be corrected by wedge grafting and internal fixation with Kirschner wires or screws.

[Results of treatment of scaphoid nonunion with microvascularized bone grafts of the 1, 2 intercompartmental supraretinacular artery and osteosynthesis]

OBJECTIVE

To analyze the results of treatment of scaphoid nonunion with questionable viability of the proximal fragment, but without significant deformity or collapse, using a vascularized bone graft of 1,2 intercompartmental supraretinacular artery (1.2 ICSRA) and subsequent osteosynthesis.

MATERIAL AND METHOD

A retrospective study was performed on 10 male patients with a radiographic diagnosis of nonunion. Functionality, pain using Visual Analog Score (VAS), grip strength, patient satisfaction and reintroduction to working life, using QuickDASH and May specific wrist scales were assessed after the treatment. The integration of the graft was checked by radiography.

RESULTS

The mean follow-up was 31.4 months, and 90% of the questionnaires were satisfactory. The VAS decreased by 4.6 points and the flexor-extensor mobility gain was 5°. The total graft consolidation rate reached 40% in 5.5 months on average.

DISCUSSION

Several studies have demonstrated better results using vascularized bone graft versus non-vascularized. From the description by Zaidemberg in 1991, the vascularized graft with 1.2 ICSRA artery, distal radius, has been the most widely used for the treatment of scaphoid nonunion.

CONCLUSIONS

Our results are comparable with the literature reviewed, thus using vascular graft of the 1.2 ICSRA and osteosynthesis with Herbert-type screw, may be an alternative treatment for proximal scaphoid nonunion, without collapse or significant deformity.

Ilizarov treatment of scaphoid nonunion

INTRODUCTION

This is single centre retrospective review of a consecutive series of patients with scaphoid nonunion (SNU) treated using the Ilizarov technique without bone graft. Fifteen of the original 18 patients were available for clinical and radiological examination at a minimum follow-up of 5 years (range 5-10 years). An evaluation was made of the late functional results, satisfaction scores, residual symptoms, grip strength and the presence of radiocarpal and scaphoid degenerative changes.

METHODS

The series consisted of 15 patients; 14 males; 1 female, with a mean SNU duration of 15.7 months, and a mean age of 23.6 years. Patients with carpal instability, humpback deformity, carpal collapse, avascular necrosis or marked degenerative change, were excluded from this treatment method. Following frame application the treatment consisted of three stages: distraction, compression and immobilisation. The technique is detailed herein.

RESULTS

Radiographic (CT) and clinical bony union was achieved in all 15 patients after a mean of 88 days (70-130 days). Mean modified Mayo wrist scores initially improved from 21 preoperatively to 86 at previous review, and were 96 at a mean follow-up of 81 months (62-120 months), with excellent results in 10, and good results seen in 5 patients. At latest review the mean grip strengths had returned to 96% of the uninjured hand, and 7 patients had regained full strength; mean wrist flexion/extension arc of motion had also continued to improve to 136° from 131°. All patients returned to their pre-injury occupations and levels of activity at a mean of 117 days. Three patients suffered superficial K-wire infections, which resolved with oral antibiotics. One patient continues to suffer intermittent mild aching in the wrist. No patient suffered loss of scaphoid height, humpback deformity, DISI instability or collapse of the regenerate bone.

CONCLUSION

In these selected patients this technique safely achieved bony union without the need to open the SNU site and without the need for bone graft. These patients also had the capacity to continually improve their wrist function beyond 3 years following their treatment.

Unstable scaphoid nonunion treatment technique: use of a volar distal radius corticocancellous autograft

Scaphoid nonunions are challenging cases that first must be identified and then treated based on stability, collapse, and vascularity. Unstable nonunions are identified on the basis of collapse of the scaphoid into the "humpback" deformity with an increased intrascaphoid and scapholunate angles. The importance of restoring normal scaphoid alignment has been stressed, because failure to do so leads to worse clinical and radiographic results with predictable patterns of radiocarpal arthrosis. We present a technique to correct unstable scaphoid nonunions using a single volar-based incision with harvesting of volar distal radius corticocancellous autograft. This technique allows the avoidance of harvest site morbidity and has union rates comparable with the gold standard of iliac crest.

Scaphoid morphology and clinical outcomes in scaphoid reconstructions

Scaphoid malunion and carpal malalignment can result after scaphoid reconstruction, if the two fragments are not properly reduced before fixation. However, currently there is no information about which degree of deformity or malalignment can be tolerated without impairing clinical function. The purpose of this study was to investigate the influence of the scaphoid morphology and carpal alignment on clinical outcomes after scaphoid reconstruction. A total of 65 patients with an average age of 29 years were followed-up after a mean period of 45 months. In all patients, osseous union after a first-time scaphoid reconstruction in the middle third had been confirmed. Scapholunate (SL) and radiolunate (RL) angles were obtained on plain radiographs as were intrascaphoid (ISA) and dorsal cortical (DCA) angles and the height/length (H/L) ratio of the reconstructed scaphoid on computed tomography (CT) scans. These parameters were correlated with clinical outcome measures. RL angles correlated significantly with wrist range of motion, grip strength and pain levels, whilst SL angles, ISA, DCA and H/L ratio failed to show significant correlations. Our data suggest that clinical outcome is correlated with correct restoration of bone morphology and carpal alignment. After reconstruction, the RL angle should not exceed 10°.

The treatment of scaphoid nonunion using the Ilizarov fixator without bone graft, a study of 18 cases

Objectives

Evaluating the safety and efficacy of the Ilizarov fine-wire compression/distraction technique in the treatment of scaphoid nonunion (SNU), without the use of bone graft.

Design

A retrospective review of 18 consecutive patients in one centre.

Patients and Methods

18 patients; 17 males; 1 female, with a mean SNU duration of 13.9 months. Patients with carpal instability, humpback deformity, carpal collapse, avascular necrosis or marked degenerative change, were excluded. Following frame application the treatment consisted of three stages: the frame was distracted 1 mm per day until radiographs showed a 2-3 mm opening at the SNU site (mean 10 days); the SNU site was then compressed for 5 days, at a rate of 1 mm per day, with the wrist in 15 degrees of flexion and 15 degrees of radial deviation; the third stage involved immobilization with the Ilizarov fixator for 6 weeks. The technique is detailed herein.

Results

Radiographic (CT) and clinical bony union was achieved in all 18 patients after a mean of 89 days (70-130 days). Mean modified Mayo wrist scores improved from 21 to 86 at a mean follow-up of 37 months (24-72 months), with good/excellent results in 14 patients. All patients returned to their pre-injury occupations and levels of activity at a mean of 117 days. Three patients suffered superficial K-wire infections, which resolved with oral antibiotics.

Conclusions

In these selected patients this technique safely achieved bony union without the need to open the SNU site and without the use of bone graft.

The unstable nonunited scaphoid waist fracture: results of treatment by open reduction, anterior wedge grafting, and internal fixation by volar buttress plate

PURPOSE

The purpose of this study is to evaluate the results of treatment of unstable nonunited scaphoid waist fracture by anterior wedge graft and internal fixation with the use of volar buttress plate and screws.

METHODS

Fourteen adult male patients with unstable nonunited scaphoid waist fracture with a humpback deformity were treated by reduction of the collapse deformity, insertion of anterior wedge graft, and internal fixation with the use of volar buttress plate and screws. The mean patient age was 26 years, and the mean duration of the nonunion before surgery was 16.5 months. The follow-up time ranged from 9 to 19 months (mean, 11 mo). Thirteen of the fourteen nonunions healed with sound radiographic union. Pre-existing avascular necrosis was a major adverse factor for achievement of union in one patient, even after a second bone-grafting procedure.

RESULTS

Union was achieved in a mean of 3.8 months. Most of the patients had satisfactory correction of scaphoid deformity and the associated dorsal intercalated segment instability. Postoperatively, improvements were seen in the range of wrist flexion and extension, grip strength, and degree of dorsal intercalated segment instability.

CONCLUSIONS

The results of the series suggest that the method of anterior wedge graft and internal fixation with the use of volar buttress plate and screws is effective for the treatment of unstable nonunited scaphoid waist fractures.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

A comparison of the use of distal radius vascularised bone graft and non-vascularised iliac crest bone graft in the treatment of non-union of scaphoid fractures

We compared two surgical techniques for the treatment of scaphoid non-union, namely, using distal radius vascularised bone graft and iliac crest non-vascularised bone graft. Eighty patients with symptomatic scaphoid non-union underwent surgical treatment, including 35 patients treated with distal radius vascularised bone graft and 45 treated by iliac crest non-vascularised bone graft. Patients were assessed objectively by examination of wrist range of motion, grip strength and radiographic findings in the postoperative period after a mean time of 2.8 (1.4) (range 1-5.2) years. Similar functional results were obtained with the two techniques. All cases of non-union in the non-vascularised group obtained consolidation in a mean time of 8.89 (2.26) months and in the vascularised group in a mean time of 7.97 (3.06) months. Three cases of consolidation failure occurred in the vascularised group and were related to technical difficulties.

Collapsed scaphoid non-union with dorsal intercalated segment instability and avascular necrosis treated by vascularised wedge-shaped bone graft and fixation

Patients with the specific problem of a collapsed Nakamura volar type, scaphoid synovial pseudarthrosis with avascular necrosis on both magnetic resonance imaging and intraoperative inspection were studied to determine the ability of a trapezoidal wedge-shaped structural bone graft vascularised by the 1,2 intercompartmental supraretinacular artery to simultaneously achieve correction of the scaphoid dimension and a high union rate. Fifteen patients with this specific problem were followed for a mean of 32.1 months and achieved union in all cases at a mean of 11.5 weeks. Improvements were seen postoperatively in wrist flexion and extension, grip strength, degree of dorsal intercalated segment instability and degree of scaphoid collapse. Two complications relating to the fixation technique occurred. Although technically difficult, it is possible to achieve a high rate of union for scaphoid pseudarthrosis while correcting substantial collapse deformity by the use of a structural, wedge-shaped, vascularised bone graft.

Does three-dimensional computer simulation improve results of scaphoid nonunion surgery?

The purpose of this study was to clarify the effectiveness of the three-dimensional computer simulations in scaphoid nonunion surgery. Seven consecutive clinical patients with scaphoid nonunion at the middle third comprised the study group. Surface models of the scaphoid were constructed on the computer using computed tomography data of the bilateral wrists in neutral position. The distal and proximal fragments of the nonunion model were matched to the mirror image of the contralateral scaphoid model. The rotation of the distal fragment relative to the proximal fragment was calculated, and reduction of the displaced fragment of the scaphoid nonunion was simulated. Similarly, the estimated bone defect and the appropriate site and direction of the screw insertion were simulated. Full-sized hard models of the bone, including a model with simulated reduction and screw insertion, then were made using stereolithography based on the computer data. In the actual surgery, reduction, bone grafting, and screw insertion were achieved using the hard models as guides. All the patients obtained solid bone fusion and substantial clinical improvement with normalized scapholunate and radiolunate angles after surgery. Three-dimensional computer simulations were found as useful for accurate correction of scaphoid nonunions and proper screw placement, which consequently leads to good clinical results.

Successful treatment of scaphoid fractures and nonunions using bioabsorbable screws: report of six cases

PURPOSE

A variety of implants have been used for the fixation of scaphoid fractures, but we have found no reports on bioabsorbable screws used for this purpose. We report 6 cases of scaphoid fractures treated with bioabsorbable screws.

METHODS

Six patients with scaphoid waist region fractures (3) and nonunions (3) treated using bioabsorbable self-reinforced poly-L-lactide screws. Interposition of a bone graft from the iliac crest was used in 4 cases. Immobilization in a short arm-thumb spica cast was applied after surgery for an average of 8 weeks.

RESULTS

Solid union was achieved in 5 cases. Using the Mayo modified Green-O'Brien wrist score, we graded the results as excellent in 1 case, good in 4 cases, and poor in the single case of nonunion.

CONCLUSIONS

These results suggest that bioabsorbable self-reinforced poly-L-lactide screws might offer an alternative in the fixation of scaphoid fractures and nonunions in the future, provided that cannulated screws of appropriate size will be available.