Scaphoid morphology and clinical outcomes in scaphoid reconstructions

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

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

Comparison of corticocancellous bone graft from the anterolateral metaphysis of the distal radius versus iliac crest for the treatment of unstable scaphoid nonunion with humpback deformity

BACKGROUND

Corticocancellous bone grafting from the iliac crest is acceptable treatment for unstable scaphoid nonunion with a viable proximal pole. However, harvesting graft from the iliac crest is associated with donor site morbidity and the requirement of general anesthesia. Thus, bone grafting from the anterolateral metaphysis of the distal radius (DR) can be a treatment option. However, no study has compared the clinical effect between the two grafting techniques.

METHODS

From 2014 to 2019, patients with unstable scaphoid nonunion with humpback deformity underwent corticocancellous bone grafting from the anterolateral metaphysis of the DR (group DR) or iliac crest (group IC). Humpback deformity was determined by evaluating the scapholunate angle (SLA) ≥ 60°, intrascaphoid angle (ISA) ≥ 45°, and radiolunate angle (RLA) ≥ 15° from preoperative radiographs and computed tomography scans. The SLA, ISA, and RLA served to gauge carpal alignment. The operative time, grip strength, active range of motion (ROM), the Modified Mayo Wrist score (MMWS), and Disabilities of Arm, Shoulder, and Hand (DASH) score were assessed postoperatively.

RESULTS

Thirty-eight patients qualified for the study (group DR, 15; group IC, 23). Union rates did not differ by patient subset (group DR, 100%; group IC, 95.7%; P = .827), and grip strength, ROM, MWS, and DASH score were similar between groups at the last follow-up. The operative time (minutes) was significantly shorter in group DR (median, 98; quartiles, 80, 114) than in group IC (median, 125; quartiles, 105, 150, P < .001). The ISA, RLA, and SLA improved postoperatively in both groups (P < 0.001). The degree of restoring carpal alignment, as evaluated by SLA, showed superior correction capability in group DR (median, 25.3% quartiles, 21.1, 35.3, P < 0.05). Donor site complications were not significantly different between the groups.

CONCLUSIONS

Corticocancellous bone graft from the anterolateral metaphysis of the DR for unstable scaphoid nonunion is associated with a shorter operation time and comparable results with that from the iliac crest in regard to union, restoration of carpal alignment, and wrist function.

LEVEL OF EVIDENCE

Level III.

360-degree Arthroscopic Management of Scaphoid Pseudarthrosis: Description of Technique and Indications

Nonunion remains one of the main complications of scaphoid fractures, with no consensus being reached as to the best surgical technique for scaphoid pseudoarthrosis. Thus, different types of procedures for bone stability and biological stimulus for consolidation have been described. The use of arthroscopy for scaphoid pseudoarthrosis has advantages as it allows for treating associated injuries, preserving wrist proprioception by minimizing damage to the joint capsule and ligaments and not deteriorating the already fragile scaphoid vasculature, leading to a quick recovery. Arthroscopy was initially indicated for stable scaphoid pseudoarthroses, being used in all patterns of this condition, including unstable ones and those with flexion collapse. However, most scientific articles describe the use of arthroscopy only through the dorsal portals, creating technical difficulty in complete debridement of the site of pseudarthrosis and in placing bone graft. This study describes the 360-degree technique, which standardizes arthroscopy in scaphoid pseudoarthrosis treatment, allowing, with the use of dorsal, volar, and radial portals, direct approach to the entire circumference of the nonunion site, facilitating the debridement of the injury site, the correction of the scaphoid deformity, and the placement of a graft directly on the site of the defect, mainly in its volar region after correction of the flexion deformity. The 360-degree technique aims to help and standardize the arthroscopic procedure for scaphoid pseudarthrosis, creating a routine with defined surgery stages. Additional portals allow complete access to the entire nonunion site and better positioning of the bone graft under direct view.

Scaphoid Malunion: Incidence, Predictors, and Outcomes

Background  Scaphoid malunion is rarely reported. Previous literature has attributed loss of carpal height and degenerative changes to scaphoid malunion, but the percentage of asymptomatic malunions remains unknown. Purpose  The authors of this study aim to define predictors of malunion and outcomes associated with scaphoid malunion. Methods  Institutional board review was obtained prior to evaluating medical records of patients 18 years and older who were treated for scaphoid fractures and/or nonunion between 2000 and 2020. The following data were collected for each patient: age, gender, fracture location, surgical technique, time to union, and whether malunion resulted. Malunion was defined using a lateral intrascaphoid angle (LISA) >45 degrees and height-to-length ratio (HLR) >60. Pain scores, range of motion (ROM), and secondary surgery were also evaluated. Results  Overall, 355 scaphoid injuries, including 196 acute fractures and 159 nonunions, were evaluated in this analysis. Of these, 55 scaphoids (15%) met the definition of malunion. Of these patients, 23% were female. The mean age at the time of injury was 29 years. Nonunion cases were more likely than acute cases to be associated with malunion. Proximal pole fractures were more likely to associated with malunion than waist fractures. When controlling for nonunion and fracture location, malunited scaphoids were not associated with any significant difference in pain score, ROM, or secondary surgery, compared with nonmalunion cases. A total of 10 patients (3.3%) without malunion and 2 patients (3.6%) with malunion went on to a secondary surgery. Final extension/flexion was 67/67 degrees and 56/59 degrees in nonmalunion and malunion groups, respectively, but these differences were not significant. Conclusion  Compared with scaphoid injuries that do not result in malunion, scaphoid injuries that heal into malunion have similar outcomes. While scaphoid malunion in a single case or series may be associated with poor outcomes, this study suggests that scaphoid malunions do not have worse functional outcomes. Level of Evidence  This is a Level IV study.

Residual flexion deformity after scaphoid nonunion surgery: 7-year follow-up study

The clinical implication of a residual flexion deformity following surgery for scaphoid nonunion is unclear. Sixty-three patients who underwent scaphoid nonunion surgery were assessed after a mean of 7 years (range 5-10) to analyse the outcomes based on the presence of residual scaphoid deformity. Primary outcome was Disabilities of the Arm, Shoulder and Hand score. Secondary outcomes were Patient-Rated Wrist Evaluation score, wrist range of motion and strength. Patients were dichotomized to residual deformity or no deformity. Scaphoid deformity was calculated from CT scans based on the median difference between the height-length ratio of the operated versus the uninjured scaphoid. There were no differences between residual deformity (n = 33) and no deformity (n = 30) in any outcome variables, except for wrist extension which was slightly worse in the deformity group. The deformity group had a greater number of radiographic osteoarthritis, but all cases were mild, and osteoarthritis did not correlate to a worse outcome. We conclude that residual scaphoid deformity has no relevant negative impact on mid-term wrist function.Level of evidence: IV.

Clinical and Patient-Reported Outcomes After Hybrid Russe Procedure for Scaphoid Nonunion

Background: Hybrid Russe technique for the treatment of scaphoid nonunion with humpback deformity has been described with a reported 100% union rate. We sought to evaluate the reproducibility of this technique. Methods: We completed a retrospective chart review of patients with a scaphoid waist nonunion and humpback deformity treated with the hybrid Russe technique from 2015 to 2019 with a minimum of 3-month follow-up. Twenty patients with 21 nonunions were included (mean follow-up: 7.0 months). Scapholunate angle was the primary outcome measure. Secondary outcomes included: intrascaphoid angle, radiolunate angle, pain on the visual analog scale (VAS), and Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score. Other variables included: time to computed tomography (CT) union, range of motion, and complications. Descriptive statistics were presented. Pre- and postoperative angles, VAS, and QuickDASH scores were evaluated with Wilcoxon signed rank tests. Results: The mean scapholunate angle improved -17.6° ± 6.4°. The mean intrascaphoid angle improved 28.2° ± 6.3°. The mean radiolunate angle improved 12.8° ± 8.8°. Of the 21 scaphoids, 20 (95%) demonstrated union on a CT scan. One patient was diagnosed with a nonunion. In total, 90% of patients noted symmetric range of motion compared with the contralateral side. The mean VAS pain score improved 6 ± 3 points. The mean QuickDASH score improved 10 ± 8 points. Complications (aside from nonunion) included 1 patient with persistent wrist pain that resolved with removal of hardware. Conclusions: The hybrid Russe technique for the treatment of scaphoid nonunions with humpback deformity demonstrates a 95% union rate. This technique is effective, reproducible, and may serve as an alternative to techniques that include structural grafts from distant sites.

Can CT-Scan Measurements of Humpback Deformity, Dislocation, and the Size of Bony Cysts Predict Union after Surgery for Scaphoid Nonunion?

Objective  Scaphoid fractures are associated with high rates of late- or nonunion after conservative treatment. Nonunion is reported to occur in approximately 10% of all scaphoid fractures. It is known that the union of scaphoid fractures is affected by factors such as location at proximal pole, tobacco smoking, and the time from injury to treatment. Same factors seem to affect the healing after surgery for scaphoid nonunion. While the impact of preoperative humpback deformity on the functional outcome after surgery has been previously reported, the impact of humpback deformity, displacement, and the presence of bony cysts on union rate and time to healing after surgery has not been studied. Purpose  The primary purpose of this study is to assess the association of humpback deformity, fragment displacement, and the size of cysts along the fracture line with the union rate and union time, following surgery of scaphoid nonunion. The second purpose of the study is to investigate the interobserver reliability in the evaluation of computed tomography (CT) scans of scaphoid nonunion. Patients and Methods  From January 2008 to December 2018, 178 patients were surgically treated in our institution. After exclusion criteria were met, 63 patients with scaphoid delayed- or established nonunion, and preoperative CT scans of high quality (<2mm./ slice), were retrospectively analyzed. There was 58 men and 5 women with a mean age of 30 years (range: 16-72 years). Four orthopaedic surgeons and one radiologist independently analyzed the CT scans. The dorsal cortical angle (DCA), lateral intrascaphoid angle (LISA), the height-to-length ratio, the size of the cysts, and displacement of the fragments were measured. Healing was defined by CT scan, or by conventional X-ray, and status of no pain at clinical examination. Thirty-two of the patients had developed nonunion (>6 months postinjury), while 31 were in a stage of delayed union (3-6 months postinjury). Results  Open surgery with cancellous or structural bone graft was the treatment of choice in 49 patients, 8 patients were treated with arthroscopic bone grafting, and 6 patients with delayed union were operated with percutaneous screw fixation, without bone graft. Overall union rate was 86% (54/63) and was achieved after 84 days (12 weeks) (mean). The failure rate and time to healing were not associated with the degree of the humpback deformity, size of the cysts, or displacement of the nonunion in general. However, greater dislocation, and the localization of the nonunion at the scaphoid waist, showed significant influence on the union rate. Dislocation at nonunion site, in the group of the patients who united after surgery, was 2.7 mm (95% confidence interval [CI]: 1.5-3.7), and in the group who did not unite was 4.2 mm (95% CI: 2.9-5.7); p  = 0.048). Time from injury to surgery was significantly correlated with time to union ( p  < 0.05), but not associated with the union rate ( p  < 0.4). Patients treated arthroscopically achieved faster healing (42 days), (standard deviation [SD]: 22.27) as compared with patients treated by open techniques (92 days; SD: 70.86). Agreement among five observers calculated as intraclass correlation coefficient was for LISA: 0.92; for height-to-length ratio: 0.73; for DCA: 0.65; for size of cysts: 0.61; and for displacement in millimeters: 0.24, respectively. Conclusions  The degree of humpback deformity and the size of cysts along the fracture line of scaphoid nonunion have no predictive value for the result, neither for the union rate nor the union time after surgery for the scaphoid nonunion. However, larger dislocation of the fragments measured at the scaphoid waist showed lower union rate. Time to healing following surgery is mainly influenced by the time from injury to the surgical treatment and may be influenced by the choice of the surgical technique. Interrater reliability calculation was best with LISA measurements, and worse with the measurements of the dislocation. Level of Evidence  This is a Level III, observational, case-control study.

Normal ranges for measurements of the scaphoid bone from sagittal computed tomography images

This study aimed to determine normal values of three parameters commonly used to determine malunion by investigating intact scaphoids on sagittal computed tomography images from healthy individuals. We analysed 62 normal scaphoids and found the mean height-length ratio, lateral intrascaphoid angle and dorsal cortical angle to be 0.58, 27° and 128°, respectively. These measurements had good-to-excellent, poor-to-moderate and moderate-to-good inter- and intra-rater reliabilities, respectively. This study provides information on normal parameters of the scaphoid that may inform clinical decision making when assessing malunion. We suggest that the lateral intrascaphoid angle should be used with great caution as a measure of deformity.Level of evidence: III.

Vascularized Bone Grafting for Scaphoid Nonunion with Humpback Deformity: The Surgical Technique

Background  Scaphoid nonunion with humpback deformity and avascular necrosis (AVN) is a challenging problem. Correction of dorsal intercalated segment instability (DISI) requires grafting of a large and hard vascularized bone segment onto the volar side of the scaphoid. Purposes  We have been treating the patients with one-incision vascularized bone grafting technique for scaphoid nonunion to improve blood supply and correct humpback deformity. We evaluated these cases retrospectively to the surgical efficacy of our procedure. Methods  We harvested vascularized bone from the dorsal side of the radius using the method by Zaidemberg et al and inserted the cortical aspect into the scaphoid volar side using a direct lateral approach. Totally, 11 patients (nine males andtwo females) with a mean age of 40 years were recruited for this study. The mean time from fracture to treatment was 6 years and 3 months. The mean preoperative radiolunate angle was 25 degrees. All the patients showed AVN of the proximal scaphoid on T1-weighted images. An averaged follow-up period was 2 years and 3 months. Results  Postoperative computed tomography revealed bony union in 10 patients (91% of union rate) with a mean modified Mayo'swrist score of 88 points (range, 75-100 points) and a mean disabilities of arm, shoulder, and hand (DASH) score of 4 points (range, 0-20 points). The mean radiolunate angle was corrected from 25 to 5 degrees. No adverse events were observed, except temporary mild paresthesia of the radial nerve territory in two patients. Conclusion  This technique effectively corrected DISI in patients with scaphoid nonunion accompanied by humpback deformity and AVN.

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.

[Comparison of scaphoid reconstruction with a non-vascularised bone graft, with and without shock waves; preliminary results]

BACKGROUND

Focused, high energy shock wave therapy (ESWT) stimulates bone healing by neo-angiogenesis and activating osteocytes. This study investigates if applying an ESWT intraoperatively improves and accelerates the healing of a scaphoid nonunion after reconstruction using a non-vascularized bone graft.

PATIENTS AND METHODS

In this prospective, ongoing study, patients with a scaphoid reconstruction using a non-vascularized bone graft and stabilization for non-union, are randomized for having additionally an intraoperative ESWT (intervention group) or not (control group). In 6 weeks-intervals, patients have a clinical and radiological follow-up, including a CT scan at 12, 18, and if needed 24 weeks postoperatively. The intervention group and the control group are compared with regard to the proportion of the bridged contact area between scaphoid and the bone graft at 12, 18, and 24 weeks postoperatively and the rate of the healed scaphoids at the final follow-up. At time of this data analysis, 35 patients of the intervention group and 33 patients of the control group had passed all of their scheduled follow-ups.

RESULTS

Twenty-four weeks postoperatively, the scaphoids of 27 patients (77 %) in the intervention group and those of 20 patients (61 %) in the control group were healed. At 12, 18, and 24 weeks, the contact area between scaphoid and the bone graft proximally was bridged by 80 %, 84 %, and 86 % respectively in the intervention group, and 74 %, 81 %, and 84 % in the control group. Distal to the bone graft, the gap was bridged by 91 %, 94 %, and 95 % for the intervention group and 77 %, 90 %, and 94 % for the control group. At 12 weeks postoperatively, the proportional healing distal to the bone graft was significantly higher after ESWT.

CONCLUSION

A single, intraoperative ESWT improves the healing rate of scaphoid reconstruction with a non-vascularized bone graft and accelerates the gap bridging during the first 12 weeks after surgery.

[3D analysis and computer assisted reconstruction for scaphoid non-union]

The odd shape of the scaphoid is a challenge to our spatial sense. Computer assistance is of an unmatched value when reconstructing a non-united scaphoid: From CT data a true 3-D-model can be generated, fully interactive; thus it can be moved, manipulated and of course also printed for hands-on experience. Comparing the virtual 3-D-models of the nonunion with the healthy contralateral scaphoid, the exact amount of the deformity is calculated which allows for the planning of an anatomically precise reconstruction of the scaphoid shape. Finally, computer generated patient specific instruments will facilitate the implementation of this planning intraoperatively. This proceeding enables us to reconstruct the non-united scaphoid markedly more accurately and with this reliably normalize wrist kinematics. Meanwhile we have applied this technique successfully in more than 50 cases of scaphoid-nonunions presenting with significant deformity.

Scaphoid Malunion Clinical and Radiographic Outcomes at a Minimum of 4 Years Follow-Up

PURPOSE

To evaluate the radiographic and clinical outcomes of patients with scaphoid malunion after acute fracture at a mean of 7 years after injury.

METHODS

Patients with scaphoid malunion were identified from a departmental database of acute scaphoid fractures. Patients with a scaphoid height-to-length ratio greater than 0.6 on final follow-up computed tomography (CT) scan were considered malunited. These patients were contacted to return for CT imaging and clinical assessment. A total of 22 patients were included (4 females and 18 males). Average age of the group was 41 years (range, 16-64 years) and average length of follow-up was 7.4 years (range, 4.4-11.8 years) after injury.

RESULTS

Ten patients who underwent CT imaging demonstrated arthritic changes at the radial styloid, scaphoid fossa, or scaphotrapeziotrapezoid joint(s). Despite this, patients had good clinical function that was not significantly different compared with the uninjured side. Patients reported minimal pain and disability based on patient-reported outcome measures, and there was a moderate correlation between passive range of motion and height-to-length ratio.

CONCLUSIONS

Nearly half of all patients with malunited acute scaphoid fractures demonstrated radiographic findings of early arthritis on CT imaging but overall good clinical results on midterm follow-up.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.

The Impact of Scaphoid Malunion on Radioscaphoid Joint Contact: A Computational Analysis

PURPOSE

The clinical relevance of scaphoid malunion is controversial because the biomechanical sequelae remain poorly understood. In this computational study, the effect of increasing scaphoid malunion on radioscaphoid joint contact was assessed.

METHODS

Six computational wrist models of active wrist flexion-extension were used to examine 6 scaphoid malunions of varying severities. The malunions were computationally created using 3-dimensional imaging software. Each scaphoid was shortened at the waist by 2 mm to simulate fracture comminution and the distal pole was angulated volarly from 15° to 55° in 10° intervals to create a total of 6 scaphoid malunion models per specimen. Each malunion model was then assessed at 3 wrist positions: neutral, 40° flexion, and 40° extension. The radioscaphoid contact area, as well as the contact centroid, was calculated.

RESULTS

There was a statistically significant association between malunion severity and a wider area of contact at the radiocar: pal joint. The centroid of this radioscaphoid contact area also moved in an ulnar direction for all tested wrist positions. In the extended wrist position, the centroid also moved volarly.

CONCLUSIONS

In this computational model, the amount of radioscaphoid joint contact was significantly increased with progressive scaphoid malunion severity. Furthermore, the position of the contact centroid had a significant change in position in the ulnar direction in all wrist positions with increasing scaphoid malunion. The clinical importance of this contact is yet to be elucidated, but this computational model serves as a basis for understanding the biomechanical consequences of scaphoid humpback deformities.

CLINICAL RELEVANCE

This study provides a computational analysis examining changes at the radioscaphoid joint that may occur within the wrist with the scaphoid malunited.

The Natural History of Scaphoid Fracture Malunion: A Scoping Review

Background  A scaphoid malunion occurs when a scaphoid fracture heals in a nonanatomic position or when the fracture is fixed without correction of the sagittal angular deformity. Although altered carpal mechanics and early osteoarthritis have been suggested as natural sequelae, the natural history and clinical outcomes are debatable. Purposes  The purpose of this study is to review and summarize the available literature regarding clinical, functional, and radiographic outcomes of patients with scaphoid malunion. Methods  A systematic search of the MEDLINE/PubMed, EMBASE, Cochrane Library, and Web of Science was performed to identify published studies concerning the clinical and radiological results of scaphoid malunion following either acute scaphoid fracture or surgically treated nonunions. Results  Five publications with a total of 83 malunions were included in the final synthesis. The diagnosis of malunion was based on computed tomography by calculating the lateral intrascaphoid angle (threshold of 35 or 45 degrees) or height/length ratio (threshold of 0.6). Self-reported and clinical evaluation techniques varied between the studies and direct comparison was not possible between the different outcome measures. Most patients demonstrated arthritic changes; however, correlation with pain and functional results was not always present. Conclusions  This scoping review confirmed that patients with malunited scaphoids seem to have higher likelihood of post traumatic arthritis. However, clinical implications remain uncertain and better methods for assessing and defining scaphoid deformity are required.

Multiplanar reformation computed tomography for carpal malalignment

Correct interpretation of scaphoid axial length and carpal malalignment is difficult owing to the complex geometry of the scaphoid. Traditional measurements, such as the scapholunate angle and radiolunate angle, have shown limited reproducibility. To improve the assessment of these measurements, we used multiplanar reformation computed tomography with added average intensity projection. Four measurements for scaphoid morphology and carpal alignment were independently measured by four observers on computed tomography scans of 39 consecutive patients who were treated conservatively for scaphoid fracture. Fleiss's kappa for categorical results showed substantial agreement for the measurements of the scapholunate and radiolunate angles. Intraclass correlation coefficients were significant for measurements of the axial length, scapholunate angle and radiolunate angle. Our results suggest that multiplanar reformation computed tomography with added average intensity projection is a reliable technique for assessment of scaphoid morphology and carpal alignment. Level of evidence: II.

Imaging for Acute and Chronic Scaphoid Fractures

The scaphoid is the most commonly fractured bone in the wrist but 20% to 40% of scaphoid fractures are radiographically occult. Delayed or misdiagnosis can have significant consequences with late complications such as nonunion, malunion, or the development of avascular necrosis in the proximal pole. After initial negative radiographs, advanced cross-sectional imaging, including CT and MRI, ultimately may provide more accurate and rapid diagnosis than conventional radiography. With chronic fractures, the preferred modality depends on the clinical question. New techniques are evolving that will further advance imaging for diagnosis and treatment of scaphoid fractures.

The Management of the Healed Scaphoid Malunion: What to Do?

Successful bone union is only a portion of scaphoid fracture management. Malunion is possible and can alter wrist kinematics, potentially causing wrist pain and accelerated degeneration. Evaluation of scaphoid malunion begins with adequate imaging and understanding of deformity. Treatment includes nonoperative management, reconstruction, or salvage options. Correction of malunion can be obtained with an osteotomy and the use of structural graft to recreate anatomy and restore normal carpal motion. Clinical improvement of symptomatic scaphoid malunion can be reliably obtained with reconstruction, although the natural history and role for intervention in asymptomatic malunions remains unclear.

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.

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.

Importance of Computed Tomography in Determining Displacement in Scaphoid Fractures

Background  Displaced scaphoid fractures have a relatively high rate of nonunion. Detection of displacement is vital in limiting the risk of nonunion when treating scaphoid fractures. Questions/Purpose  We evaluated the ability to diagnose displacement on radiographs and computed tomography (CT), hypothesizing that displacement is underestimated in assessing scaphoid fracture by radiograph compared with CT. Materials and Methods  Thirty-five preoperative radiographs and CT scans of acute scaphoid fractures were evaluated by two blinded observers. Displacement and angular deformity were measured, and the fracture was judged as displaced or nondisplaced. Scapholunate, radiolunate, and intrascaphoid angles were measured. Radiograph and CT measurements between nondisplaced and displaced fractures were compared. Intraobserver reliability was measured. Results   Reader 1 identified 12 fractures as nondisplaced on radiograph, but displaced on CT (34%). Reader 2 identified 9 fractures as nondisplaced on radiograph, but displaced on CT (26%). For displaced fractures, the mean intrascaphoid angle was over three times greater when measured on CT than on radiograph (56 vs. 16 degrees). Scapholunate angle >65 degrees and radiolunate angle >16 degrees were significantly associated with displacement on CT. Interobserver reliability for diagnosing displacement was perfect on CT but less reliable on radiograph. Conclusion  Scaphoid fracture displacement on CT was identified in 26 to 34% of fractures that were nondisplaced on radiograph, confirming that radiographic evaluation alone underestimates displacement. These results underscore the importance of CT scan in determining displacement and angular deformity when evaluating scaphoid fractures, as it may alter the decision on treatment and surgical approach to the fracture. We recommend considering CT scan to evaluate all scaphoid fractures. Level of Evidence  Level III.

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.

Is there a trend in CT scanning scaphoid nonunions for deformity assessment?-A systematic review

PURPOSE

The effect of scaphoid nonunion deformity on wrist function is uncertain due to the lack of reliable imaging tools. Advanced three-dimensional (3-D) computed tomography (CT)-based imaging techniques may improve deformity assessment by using a mirrored image of the contralateral intact wrist as anatomic reference. The implementation of such techniques depends on the extent to which conventional CT is currently used in standard practice. The purpose of this systematic review of medical literature was to analyze the trend in CT scanning scaphoid nonunions, either unilaterally or bilaterally.

MATERIALS AND METHODS

Using Medline and Embase databases, two independent reviewers searched for original full-length clinical articles describing series with at least five patients focusing on reconstructive surgery of scaphoid nonunions with bone grafting and/or fixation, from the years 2000-2015. We excluded reports focusing on only nonunions suspected for avascular necrosis and/or treated with vascularized bone grafting, as their workup often includes magnetic resonance imaging. For data analysis, we evaluated the use of CT scans and distinguished between uni- and bilateral, and pre- and postoperative scans.

RESULTS

Seventy-seven articles were included of which 16 were published between 2000 and 2005, 19 between 2006 and 2010, and 42 between 2011 and 2015. For these consecutive intervals, the rates of articles describing the use of pre- and postoperative CT scans increased from 13%, to 16%, to 31%, and from 25%, to 32%, to 52%, respectively. Hereof, only two (3%) articles described the use of bilateral CT scans.

CONCLUSION

There is an evident trend in performing unilateral CT scans before and after reconstructive surgery of a scaphoid nonunion. To improve assessment of scaphoid nonunion deformity using 3-D CT-based imaging techniques, we recommend scanning the contralateral wrist as well.

Dorsal intercalated segmental instability associated with malunion of a reconstructed scaphoid

We analysed scaphoid deformity as a result of surgical treatment of scaphoid fracture nonunion and assessed the deformity associated with a dorsal intercalated segmental instability pattern of carpal malalignment. A total of 45 patients who were treated for scaphoid fracture nonunion were included in the study. The height-to-length ratio of the scaphoid was measured on computed tomographic images and used to assess scaphoid deformity. Carpal malalignment was quantified based on the radio-lunate angle. A correlation analysis between the height-to-length ratio and the radio-lunate angle was performed. Dorsal intercalated segmental instability was defined as a radio-lunate angle >15°, and a receiver operating curve analysis was used to calculate the cutoff height-to-length ratio that can be accompanied with dorsal intercalated segmental instability. Extension of the lunate increases in proportion to the flexion deformity of the scaphoid; dorsal intercalated segmental instability can occur if the height-to-length ratio of the scaphoid is >0.73.

LEVEL OF EVIDENCE

IV.

Acute Scaphoid Fractures: A Critical Analysis Review

Nondisplaced scaphoid fractures can be effectively treated nonoperatively, with union rates approaching or, in some series, exceeding the rates attained with operative intervention. The evidence supports equal outcomes when using a short arm or long arm cast for the closed treatment of nondisplaced scaphoid fractures. Also, equivalent outcomes have been demonstrated with or without a thumb spica component to the cast. Operative intervention is the recommended treatment for displaced scaphoid fractures. Advanced imaging should be obtained if clinical suspicion is present for a scaphoid fracture with negative radiographs more than 2 weeks after the injury. In some settings, it may even be more cost-effective to obtain advanced imaging sooner.

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.

Analysis of deformity in scaphoid non-unions using two- and three-dimensional imaging

Pre-operative assessment of the deformity in scaphoid non-unions influences surgical decision-making. To characterize deformity, we used three-dimensional computed tomographic modelling in 28 scaphoid non-unions, and quantified bone loss, dorsal osteophyte volume and flexion deformity. We further related these three-dimensional parameters to the intrascaphoid and capitate-lunate angles, and stage of scaphoid non-union advanced collapse assessed on conventional two-dimensional images and to the chosen surgical procedure. Three-dimensional flexion deformity (mean 26°) did not correlate with intrascaphoid and capitate-lunate angles. Osteophyte volume was positively correlated with bone loss and stage of scaphoid non-union advanced collapse. Osteophyte volume and bone loss increased over time. Three-dimensional modelling enables the quantification of bone loss and osteophyte volume, which may be valuable parameters in the characterization of deformity and subsequent decision-making about treatment, when taken in addition to the clinical aspects and level of osteoarthritis.

TYPE OF STUDY/LEVEL OF EVIDENCE

Level IV.

Three-Dimensional Assessment of Bilateral Symmetry of the Scaphoid: An Anatomic Study

Preoperative 3D CT imaging techniques provide displacement analysis of the distal scaphoid fragment in 3D space, using the matched opposite scaphoid as reference. Its accuracy depends on the presence of anatomical bilateral symmetry, which has not been investigated yet using similar techniques. Our purpose was to investigate symmetry by comparing the relative positions of distal and proximal poles between sides. We used bilateral CT scans of 19 adult healthy volunteers to obtain 3D scaphoid models. Left proximal and distal poles were matched to corresponding mirrored right sides. The left-to-right positional differences between poles were quantified in terms of three translational and three rotational parameters. The mean (SD) of ulnar, dorsal, and distal translational differences of distal poles relative to proximal poles was 0.1 (0.6); 0.4 (1.2); 0.2 (0.6) mm and that of palmar rotation, ulnar deviation, and pronation differences was −1.1 (4.9); −1.5 (3.3); 1.0 (3.7)°, respectively. These differences did not significantly differ from zero and thus were not biased to left or right side. We proved that, on average, the articular surfaces of scaphoid poles were symmetrically aligned in 3D space. This suggests that the contralateral scaphoid can serve as reference in corrective surgery. No level of evidence is available.

Arthroscopic Management of Scaphoid Nonunions

The difficulty in healing scaphoid nonunions is challenged further by the dynamic, unstable nature of the fracture-fragment interface. Recently, several investigators have introduced a minimally invasive technique for scaphoid nonunion repair, which has the advantages of minimal morbidity and accurate articular reduction, resulting in less postoperative stiffness and increased functional outcomes. However, failure to recognize the critical steps during minimally invasive surgery can result in incorrect treatment or limit any chances for successful bone repair. We reviewed the selected literature pertinent to arthroscopic techniques in the treatment of scaphoid nonunions. Furthermore, we presented a new arthroscopic approach that can be used in place of traditional formal open exposures in challenging cases of nonunion.

Clinical outcome of scaphoid malunion as a result of scaphoid fracture nonunion surgical treatment: A 5-year minimum follow-up study

BACKGROUND

Although malunion resulting from reconstruction for scaphoid fracture nonunion is a typical complication, there has been little consideration regarding its clinical outcomes.

HYPOTHESIS

The quality of restoration of the scaphoid anatomy may have little effect on clinical outcomes.

MATERIALS AND METHODS

Twenty-five patients with scaphoid fracture nonunion underwent curettage and internal fixation with bone grafting performed by a single surgeon, and they were followed up for a minimum of 5 years. Some of these patients comprised the malunion group if the height/length ratio (H/L ratio) in the most central longitudinal computed tomographic image was more than 0.6. We compared the clinical outcomes of the malunion group with a well-union group based on various clinical scores (Patient Evaluation Measure, Disabilities of the Arm, Shoulder and Hand, modified Mayo wrist scoring system).

RESULTS

The average follow-up period was 81 months (range: 65-110), and 15 cases among the 25 patients were included in the malunion group. There were no statistical differences in the clinical scores between malunions (15 cases) and well unions (10 cases), and there was no correlation between the H/L ratios and the clinical outcomes.

CONCLUSION

The clinical outcomes of malunited scaphoids after reconstruction for scaphoid fractures nonunion did not differ significantly from well-united scaphoids at a minimum 5-year follow-up.

Arthroscopic management of chronic unstable scaphoid nonunions: effects on restoration of carpal alignment and recovery of wrist function

PURPOSE

The purpose of this study was to assess the effects of arthroscopically assisted reduction and osteosynthesis on restoration of carpal alignment and recovery of clinical wrist function in patients with unstable scaphoid nonunion.

METHODS

Thirty-six patients who underwent arthroscopically assisted osteosynthesis with or without bone grafting for unstable scaphoid nonunion between July 2006 and January 2012 were enrolled. The average time from injury to surgery was 51 ± 78.3 months. Radiographic and clinical evaluations were assessed on preoperative and postoperative days, and follow-up evaluation took place at a minimum of 24 months.

RESULTS

Union was achieved in 86% (31 of 36) of patients at a mean of 11 ± 2.7 weeks. Scaphoid axial length (SAL), lateral intrascaphoid angle (ISA), scapholunate angle (SLA), and reversed carpal height ratio (CHR) was significantly improved after surgery, and those correction ratios averaged 66% ± 46.8%, 74% ± 58.2%, 81% ± 59.8%%, and 94% ± 46%, respectively. The range of wrist motion was unchanged after surgery, but the grip strength improved from 74% ± 22.1% preoperatively to 89% ± 13.7% postoperatively compared with the contralateral side (P = .042). Mean Disabilities of the Arm, Shoulder, and Hand (DASH) and Patient-Related Wrist Evaluation (PRWE) scores improved significantly (P < .001) from 44 and 51 preoperatively to 13 and 23 postoperatively, respectively. The radiological parameters of the scaphoid and carpal alignment in patients who achieved bony union did not correlate with clinical wrist function.

CONCLUSIONS

Arthroscopic reduction and osteosynthesis of chronic unstable scaphoid nonunion is limited for restoration of normal carpal alignment but has positive effects on the recovery of clinical wrist function.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Scaphoid nonunions in skeletally immature adolescents

Scaphoid nonunions in children requiring operative treatment are rare. The aim of this study was to analyze our own patient population of the last 13 years to assess the postoperative outcome of these operations. Seven patients, under aged 14 years, were treated for scaphoid nonunions. Patients were clinically and radiologically examined and subjective outcomes were measured, such as the visual analogue pain scale (VAPS), Disability of the Arm, Shoulder and Hand (DASH) score, and Krimmer score. All patients showed an excellent outcome, as determined by the DASH score, Krimmer score, and VAPS. No differences between grip strength and range of motion between the operated and non-operated hand were observed. Therefore, we propose that scaphoid nonunions in skeletally immature adolescents can be treated satisfactorily with excision of the nonunion and bone grafting.

Reliability and validity of carpal alignment measurements in evaluating deformities of scaphoid fractures

PURPOSE

Several radiographic carpal alignment indices are used to evaluate the deformities of scaphoid fractures. The purpose of this study was to determine the reliabilities and validities of radiographic carpal alignment indices commonly used to evaluate deformities of scaphoid fractures.

METHODS

Thirty-six patients with a scaphoid fracture were evaluated. Five carpal alignment indices were assessed on lateral plain radiographs, namely, scapholunate angle, radioscaphoid angle, radiolunate angle, radiocapitate angle, and capitolunate angle. Three examiners measured these radiographic indices at two sessions, and intraobserver and interobserver reliabilities were determined and expressed as intraclass correlation coefficients. Discriminant validities of radiographic carpal alignment indicies between injured and uninjured wrists were evaluated. For convergent validity testing, the correlation between the radiographic carpal alignment indices and intrascaphoid angles (ISAs) or height-to-length (HL) ratios on CT longitudinal scans was assessed. Further, carpal alignment indices after surgical reconstruction were compared to the Mayo wrist score.

RESULTS

Scapholunate and radiolunate angles had the highest reliabilities, and radiocapitate angle had the lowest. Radiolunate angle had the highest discriminant validity followed by scapholunate, and capitolunate angles. In convergent validity testing, scapholunate angles and radiolunate angles correlated with ISA angles, and radiolunate and capitolunate angles correlated with HL ratios. Only the radiolunate angles correlated with the Mayo wrist scores.

CONCLUSIONS

Among radiographic carpal alignment measures, radiolunate angle is the most reliable and valid carpal alignment index for evaluating deformities of scaphoid fractures. Scapholunate and capitolunate angles could be used as an alternative, but have less validity.