Measurement of the scaphoid humpback deformity using longitudinal computed tomography: intra- and interobserver variability using various measurement techniques

Subchondral Radial and Ulnar K-Wire Positioning With Cancellous Bone Graft Shortens Union Time in Scaphoid Waist Nonunion

BACKGROUND

Bone grafting in patients with scaphoid waist nonunion can present several technical challenges. In this study, we aimed to present a modified surgical technique for scaphoid waist nonunion, which consisted of subchondral radial and ulnar K-wires positions with cancellous bone graft, and to compare the clinical outcome of this modified technique with the conventional method.

METHODS

We retrospectively reviewed 72 patients with scaphoid waist nonunion who had been surgically treated between January 2011 and December 2020. Of these, 34 patients were treated with the modified method and 38 with the conventional method. Debridement of the nonunion site was performed using a curette, rongeur, and microburr. Two or 3 K-wires were inserted along the cancellous portion of the scaphoid in the conventional method. In the modified method, 2 K-wires were inserted along the ulnar and radial subchondral portion of the scaphoid to increase the space for bone grafting in the cancellous portion of the scaphoid. The autologous cancellous bone grafted in both the methods. Demographic, radiological, and clinical outcomes were reviewed and compared between the groups.

RESULTS

There were no significant differences in demographics and characteristics of nonunion between the 2 groups of patients. The modified method group showed significantly shorter union time than the conventional method group (conventional group: 13.0 ± 1.3 weeks, modified group: 11.4 ± 1.1 weeks; P < 0.001). The bony union rate was 97.1% for the modified method and 89.5% for the conventional method. Satisfactory clinical outcomes (excellent and good Mayo wrist scores) were achieved in 27 cases (81.8%) using the modified method and 22 cases (64.7%) using the conventional method.

CONCLUSION

Subchondral radial and ulnar K-wire positioning with cancellous bone graft (modified method) can improve the union time with satisfactory clinical outcomes in the treatment of scaphoid waist nonunion.

Cancellous bone graft from the distal radius and headless screw fixation for unstable scaphoid waist nonunion

PURPOSE

Cancellous bone harvested from the distal radius has been used in various hand surgeries, but studies on its use in scaphoid waist nonunions are insufficient. We investigated the usefulness of cancellous bone graft from the distal radius and headless screw fixation in unstable scaphoid waist nonunion.

METHODS

Thirty-one patients who underwent cancellous bone graft from the distal radius and headless screw fixation for unstable scaphoid waist nonunion with follow-up for at least 1 year were included. Bone union time, the number of patients with bone union at six and 12 weeks, total number of patients with bone union at last follow-up, and bone union on the computed tomography (CT) image at postoperative six weeks were evaluated. Further, pre- and postoperative radiological measurements, such as scaphoid length and height, lateral intra-scaphoid angle, and height-to-length ratio, and functional outcomes were compared. Additionally, inter-observer reliability of radiologic parameters was checked.

RESULTS

Bone union was achieved in 29 patients. There were two nonunions (6.5%). Bone union time was 10.7 (range, 6-26) weeks. Eighteen (58%) and 25 patients (80.6%) were diagnosed with bone union on the plain radiographs at six and 12 weeks, respectively. Twenty-two patients (71%) were diagnosed with bone union on CT performed at six weeks. Radiological measurements and functional outcomes improved postoperatively. The scaphoid length showed good inter-observer agreement.

CONCLUSIONS

In treating unstable scaphoid waist nonunion, cancellous bone graft from the distal radius and headless screw fixation achieved 93.5% union and improved radiological measurements as well as functional outcomes.

The "Standing Peanut" Scaphoid View: A Semi-supinated Radiographic View for Intraoperative Evaluation of Screw Placement in Scaphoid Waist Fractures

Scaphoid waist fractures are the most common fracture of the scaphoid. Operative management is indicated with unstable fractures and often for nondisplaced waist fractures to decrease time to union and return to work/sport. Screw placement within the central axis of the scaphoid is paramount and correlates with outcomes. Assessment of intrascaphoid screw placement is classically done via intraoperative fluoroscopy. An additional fluoroscopic view is presented to assist in confirming implant positioning. Along with the standard anterioposterior, lateral, pronated oblique, and "scaphoid" view we obtain a "standing peanut" view for assessment of central screw placement. This view also allows for further evaluation of center/center positioning and better assessment of fixation crossing the fracture into the proximal pole. The "standing peanut" view is best obtained in a sequential manner beginning with the forearm in neutral rotation. First, the forearm is then supinated 30 degrees; next, the wrist is placed at 45 degrees of ulnar deviation. Then finally, 10 degrees of wrist extension. We utilize this additional intraoperative view in conjunction with the standard fluoroscopic views for assessing and ensuring center-center implant positioning, particularly within the proximal pole. When ensuring center-center positioning, we prefer this view as an adjunct view to the standard fluoroscopic views intraoperatively. It provides a beneficial view of the proximal pole delineating the number of screw threads that have obtained proximal pole purchase. We have found it particularly useful in the setting of scaphoid waist fracture nonunion with the classic 'humpback' deformity after correction with volar interposition grafting. Standard radiographic views may be misinterpreted regarding implant positioning if there remains any residual flexion. The view requires little in the way of training to obtain once appreciated and exposes the patient to minimal additional radiation.

Results of arthroscopic cancellous bone grafting for treatment of scaphoid nonunion in comparison with open cancellous bone grafting

This study primarily aimed to report the outcome of the arthroscopic cancellous bone grafting technique for treating scaphoid nonunion. The secondary aim was to compare the bone union rate and time, and the ability to correct the angulation of the scaphoid, between arthroscopically treated patients (n = 27), and patients treated with open cancellous bone grafting (n = 27). Nine surgeons (two in the arthroscopic and seven in the open group) with Level III experience operated on the patients. The pain score, grip strength and Quick Disability of the Arm, Shoulder and Hand score improved significantly after the arthroscopic treatment (p = 0.0001). Arthroscopic cancellous bone grafting achieved union in 25 out of 27 patients. A retrospective comparison with open cancellous bone grafting showed four nonunions. Arthroscopically treated patients healed 5.4 weeks faster compared with the open group (p = 0.033). Patients treated with open grafting had a higher risk of failure (odds ratio = 2.17), although this was not found significant (p = 0.39). The open method corrected the angulation deformity better (dorsal cortical angle correction of 4°) than the arthroscopic method (dorsal cortical angle correction of 1°), but this was not statistically significant neither within the groups (p = 0.55, p = 0.87) nor postoperatively between the groups (p = 0.98). The height-to-length ratio was not different before and after the surgery for the arthroscopic group (p = 0.44) and the open group (p = 0.27), or postoperatively between the groups (p = 0.44).Level of evidence: III.

Scaphoid Length Loss Following Nonunion Is Associated with Dorsal Intercalated Segment Instability

Background  Dorsal intercalated segment instability (DISI) in scaphoid nonunions is frequently attributed to fracture location relative to ligamentous attachments onto the scaphoid apex. We hypothesize scaphoid length loss to have a stronger correlation with DISI deformity than fracture location in patients with scaphoid nonunion. Questions/Purposes  To investigate the correlation between (1) scaphoid length loss, (2) fracture location relative to the scaphoid apex, and (3) type of nonunion (Herbert classification) and DISI deformity in skeletally mature patients with scaphoid nonunion. Patients and Methods  Twenty-seven cases of computed tomography (CT)-confirmed scaphoid nonunion (>6 months) were retrospectively included. Our primary outcome was the degree of DISI as measured by the radiolunate (RL) angle on CT. Scaphoid length loss was expressed as height-to-length (H/L) ratio. Fracture location was classified as proximal or distal to the scaphoid apex. Nonunions were classified as fibrous unions (type D1) or pseudoarthrosis (type D2). The correlation between RL angle, H/L ratio, fracture location, and nonunion type was evaluated. Results  H/L ratio was the only factor associated with the degree of DISI as measured by RL angle. As scaphoid length loss increased (increasing H/L ratio), the RL angle increased. There was no significant difference in RL angle between fractures located proximal (30 degrees) or distal (28 degrees) to the scaphoid apex, or type D1 (31 degrees) versus type D2 (28 degrees) nonunions. There was no correlation between patient age, sex, or wrist side affected and RL angle. Conclusions  Scaphoid length loss, rather than fracture location, is correlated to the degree of DISI deformity in patients with scaphoid nonunion. This highlights the importance of restoring scaphoid height when planning scaphoid nonunion reconstruction. Level of Evidence  Level III, diagnostic study.

Arthroscopic versus open cancellous bone grafting for scaphoid delayed/nonunion in adults (SCOPE-OUT): study protocol for a randomized clinical trial

BACKGROUND

Scaphoid non-union results in pain and decreased hand function. Untreated, almost all cases develop degenerative changes. Despite advances in surgical techniques, the treatment is challenging and often results in a long period with a supportive bandage until the union is established. Open, corticocancellous (CC) or cancellous (C) graft reconstruction and internal fixation are often preferred. Arthroscopic assisted reconstruction with C chips and internal fixation provides minimal trauma to the ligament structures, joint capsule, and extrinsic vascularization with similar union rates. Correction of deformity after operative treatment is debated with some studies favouring CC, and others found no difference. No studies have compared time to union and functional outcomes in arthroscopic vs. open C graft reconstruction. We hypothesize that arthroscopic assisted C chips graft reconstruction of scaphoid delayed/non-union provides faster time to union, by at least a mean 3 weeks difference.

METHODS

Single site, prospective, observer-blinded randomized controlled trial. Eighty-eight patients aged 18-68 years with scaphoid delayed/non-union will be randomized, 1:1, to either open iliac crest C graft reconstruction or arthroscopic assisted distal radius C chips graft reconstruction. Patients are stratified for smoking habits, proximal pole involvement and displacement of > / < 2 mm. The primary outcome is time to union, measured with repeated CT scans at 2-week intervals from 6 to 16 weeks postoperatively. Secondary outcomes are Quick Disabilities of the Arm, Shoulder and Hand (Q-DASH), visual analogue scale (VAS), donor site morbidity, union rate, restoration of scaphoid deformity, range of motion, key-pinch, grip strength, EQ5D-5L, patient satisfaction, complications and revision surgery.

DISCUSSION

The results of this study will contribute to the treatment algorithm of scaphoid delayed/non-union and assist hand surgeons and patients in making treatment decisions. Eventually, improving time to union will benefit patients in earlier return to normal daily activity and reduce society costs by shortening sick leave.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05574582. Date first registered: September 30, 2022. Items from the WHO trial registry are found within the protocol.

How Is Scaphoid Malunion Defined: A Systematic Review

BACKGROUND

Abnormal scaphoid alignment after fracture is used as an indication for fixation. Acceptable alignment after reduction and fixation of scaphoid fractures is not well defined. We systematically reviewed the literature to identify how scaphoid malunion is currently defined and by what parameters.

METHODS

A systematic review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Multiple databases were searched for studies published in the English language that reported on outcomes after scaphoid malunion and included measurements to define malunions. Radiographic scaphoid measurement parameters were collected. Clinical outcome measures recorded included grip strength, wrist range of motion, and patient-reported outcome measures. Study quality was analyzed using the Methodological Index for Non-Randomized Studies (MINORS) criteria. Descriptive summaries of the studies are presented.

RESULTS

The initial search yielded 1600 articles. Ten articles (161 participants, 93% males, mean age = 28.3 + 6.3 years, mean MINORS score = 10.2 + 1.6) were included and analyzed. Scaphoid malunion was defined if the lateral intrascaphoid angle (LISA) was >45° (3 articles), LISA >35° (1 article), and height to length ratio >0.6 (3 articles). Four out of 5 studies found no significant associations between patient outcomes and degree of scaphoid malunion measured on imaging.

CONCLUSIONS

There is a lack of consensus for defining scaphoid malunion on imaging and absence of correlation between findings on imaging and patient outcomes. Future studies defining scaphoid malunion should be appropriately powered, incorporate measures of intrarater and interrater reliabilities for all reported imaging measurements, and utilize validated patient-reported outcome measures to reflect that malunion is associated with inferior outcomes meaningful to patients.

Double screw versus angular stable plate fixation of scaphoid waist nonunions in combination with intraoperative extracorporeal shockwave therapy (ESWT)

INTRODUCTION

Over the past years, different fixation techniques focused on rotational stability in order to increase stability and stimulate union rates. Additionally, extracorporeal shockwave therapy (ESWT) has gained importance in the treatment of delayed and nonunions. Purpose of this study was to compare the radiological and clinical outcome of two headless compression screws (HCS) and plate fixation in scaphoid nonunions, in combination with intraoperative high energy ESWT.

MATERIALS AND METHODS

Thirty-eight patients with scaphoid nonunions were treated by using a nonvascularized bone graft from the iliac crest and stabilization with either two HCS or a volar angular stable scaphoid plate. All patients received one ESWT session with 3000 impulses and energy flux per pulse of 0.41 mJ/mm² intraoperatively. Clinical assessment included range of motion (ROM), pain according to the Visual Analog Scale (VAS), grip strength, disability of the Arm Shoulder and Hand Score, Patient-Rated Wrist Evaluation Score, Michigan Hand Outcomes Questionnaire and modified Green O'Brien (Mayo) Wrist Score. To confirm union, a CT scan of the wrist was performed.

RESULTS

Thirty-two patients returned for clinical and radiological examination. Out of these, 29 (91%) showed bony union. All patients treated with two HCS compared to 16 out of 19 (84%) patients treated by plate showed bony union on the CT scans. The difference was not statistically significant. However, at a mean follow-up interval of 34 months, no significant differences could be found in ROM, pain, grip strength and patient-reported outcome measurements between the two HCS and plate group. Height-to-length ratio and capitolunate angle improved significantly in both groups compared to preoperative.

CONCLUSIONS

Scaphoid nonunion stabilization by using two HCS or angular stable volar plate fixation and intraoperative ESWT results in comparable high union rates and good functional outcome. Due to the higher rate for a secondary intervention (plate removal), HCS might be preferable as first choice, whereas the scaphoid plate fixation should be reserved for recalcitrant (substantial bone loss, humpback deformity or failed prior surgical intervention) scaphoid nonunions.

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.

Wrist angle measurements in predicting the presence of a displaced scaphoid fracture

PURPOSE

Early diagnosis and treatment of scaphoid fractures is critical to achieve union and prevent wrist degenerative arthritis. Plain radiographic measurements can guide the early approach to suspected fractures. Specifically, the ability to predict fracture or fracture stability from plain radiographs may allow the traumatologist to expand initial referral to three-dimensional imaging. We evaluated the ability of four measured angles to predict presence of a scaphoid fracture and stability.

METHODS

Fifty patients with a scaphoid fracture and 50 patients without fracture were evaluated for the cortical ring sign, scapho-lunate gapping, lateral scapholunate (SL), radio-scaphoid (RS), radio-lunate (RL), and radio-capitate (RC) angles by two-blinded observers.

RESULTS

Measurement of an increased SL interval was associated with the presence of a scaphoid fracture as diagnosed on three-dimensional imaging [odds ratio (OR) 3.0, confidence interval (CI) 1.53-5.87, p =  < 0.01]. The measured RL angle was associated with fracture displacement (OR 1.13, 95% CI 1.02-1.25, p = 0.02).

CONCLUSIONS

Scapholunate gapping on plain radiographs in the context of a clinically suspected scaphoid fracture should increase suspicion for a fracture and may prompt earlier 3-dimensional imaging, while the presence of an abnormal radiolunate angle should increase wariness for instability and can be used in preoperative planning.

The Effect of Malunited Scaphoid Fractures on Joint Congruency

PURPOSE

Although the consequences of scaphoid nonunion have been well-established, the implications of malunions are not well-known. To date, malunions have mainly been studied with 2-dimensional imaging. The objective of this study was to employ 3-dimensional computed tomography (CT) imaging and inter-bone distance mapping to determine the implications of a scaphoid malunion on 3-dimensional joint surface area (JSA) (a measure of joint contact area) at an average of 7 ± 2 years (range, 4-12 years) after fracture.

METHODS

In 14 subjects with previous unilateral, malunited scaphoid fractures, we measured the 3-dimensional JSA using reconstructed CT bone models of the carpus. The JSA was compared within each individual, comparing images of the wrist collected at the time of fracture (baseline) and 7 years later (follow-up CT scans).

RESULTS

There was a significant increase in the measured JSA (reduced joint space) at the scaphotrapezial (23% increase) and scaphocapitate (13% increase) joints when the baseline and follow-up scans of the wrist were compared. An increased JSA indicates that the 2 opposing surfaces are closer in contact and have a reduced joint spacing reflective of degenerative changes. However, participants in this study showed no radiographic signs of degenerative changes in the wrists at midterm follow-up.

CONCLUSIONS

An increase in JSA was found in patients with a malunited scaphoid in the scaphotrapezial and scaphocapitate joints of the wrist an average of 7 years after injury, but these joint changes were not evident in measured radiographic signs of arthritis.

CLINICAL RELEVANCE

As early as 4 years after injury, the 3-dimensional JSA is significantly increased at the scaphocapitate and scaphotrapezial joints. Future work is needed to determine the implication of this increased in 3-dimensional JSA on the underlying subchondral bone, and to observe these patients for longer to determine whether degenerative changes develop.

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.

The effect of reformatting axis of computed tomography scans on the measurement of deformities in scaphoid waist nonunion

BACKGROUND

Computed tomography (CT) has been used to understand the deformity of scaphoid nonunion, but no standard protocol for the reformatting of scaphoid CT imaging exists. The purpose of this study was to compare the reliability of measurements of the deformity of scaphoid waist nonunion between CT-scans reformatted in line with the scaphoid long axis and CT-scans reformatted in line with the wrist axis.

HYPOTHESIS

We hypothesized that CT-scan which was reformatted along the scaphoid long axis is more reliable for understanding the deformity of scaphoid waist nonunion.

PATIENTS AND METHODS

CT-scans of 28 wrists with a scaphoid waist nonunion were reformatted along both the long axis of the scaphoid and of the wrist. For each set of CT-scans, the nonunion gap in axial, coronal and sagittal series, the intrascaphoid angle, and the height to length ratio were measured. All scans were reviewed twice by three observers and intraclass correlation coefficients (ICCs) for inter- and intraobserver reliability were assessed.

RESULTS

For the measurement of nonunion gaps and height to length ratio, neither inter- nor intraobserver reliability showed significant differences between the two reformatting scans. However, for the intrascaphoid angle, both inter- (ICC: 0.202 vs. 0.419, p<0.001) and intraobserver (ICC: 0.614 vs. 0.790, p<0.001) reliability were significantly higher on scaphoid axis CT-scan than on wrist axis CT-scan.

DISCUSSION

In the assessment of deformity in patients with scaphoid waist nonunion, scaphoid axis reformatting CT-scans showed superior reliability for the measurement of intrascaphoid angle than did wrist axis reformatting CT-scans. Although there are several limitations for the correct assessment of all three-dimensional deformity, scaphoid axis reformatting CT-scans could help in assessing the extent of humpback deformity in patients with scaphoid waist nonunion.

LEVEL OF EVIDENCE

IV; diagnostic.

Volar rerouting of the 1,2 intercompartmental supraretinacular artery vascularized bone graft for middle and distal scaphoid nonunions

BACKGROUND

The bone graft vascularized by the 1,2 intercompartmental supraretinacular artery (1,2 ICSRA) placed on the scaphoid by a dorsal approach is a technique used to treat scaphoid nonunions with avascular necrosis of the proximal pole and without significant bone loss or carpus collapse. We present the results of patients treated with a volar rerouting of the 1,2 ICSRA graft under the tendons of the first extensor compartment to treat more distal scaphoid nonunions than the proximal pole. The aim of this study was to assess the clinical and radiological outcomes of patients operated with this technique with the hypothesis that it would allow to treat more distal nonunions than those of the proximal pole.

PATIENTS AND METHODS

This retrospective study involved patients treated by a volar rerouting of the 1,2 ICSRA graft for nonunions of the middle and distal thirds of the scaphoid. Assessments included clinical outcomes and radiological bone consolidation. QuickDASH and Mayo Wrist scores were computed. Range of motion and grip strength were evaluated for both the operated and the contralateral sides.

RESULTS

Nineteen patients were followed-up for 33 months (range: 6-75). Mean postoperative QuickDASH score was 10 (range: 0-45), and mean Mayo wrist score was 85 (range: 50-100). Flexion and extension, ulnar and radial deviations were statistically different between the affected and healthy sides (p<0,05). Consolidation was achieved in 17 patients (89%).

DISCUSSION

This technical modification allowed good functional outcomes and scaphoid consolidation. It expands the classic indications of the vascularized 1,2 ICSRA bone graft to more distal nonunions than the proximal pole.

LEVEL OF EVIDENCE

IV.

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.

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.

Structural Versus Nonstructural Bone Grafting for the Treatment of Unstable Scaphoid Waist Nonunion Without Avascular Necrosis: A Randomized Clinical Trial

PURPOSE

We evaluated the impact of structural versus nonstructural bone grafting on the time to union, scaphoid deformity correction, and clinical outcomes in adults with unstable scaphoid waist nonunion without avascular necrosis. We hypothesized that nonstructural grafting would provide earlier time to union, restoration of scaphoid anatomy, and equivalent clinical outcomes compared with structural grafting.

METHODS

We prospectively randomized 98 patients to undergo open reduction, iliac crest bone grafting with either corticocancellous (CC group) or cancellous bone only (C-only), and internal fixation using a Herbert screw. The lateral intrascaphoid angle (LISA) and scaphoid height length ratio (HLR) were measured on wrist computed tomography scans along the scaphoid longitudinal axis before surgery and an average of 84 weeks afterward. Pain, range of motion, grip strength, and Quick-Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score were measured before surgery and an average 84 weeks afterward.

RESULTS

The trajectory of scaphoid union showed a higher union rate of the C-only group at 12, 14, and 16 weeks after surgery. However, at 24 weeks after surgery, there was no difference between the groups, The union rate was 94% in patients treated with C-only and 90% with CC grafting. In patients with preoperative LISA less than 70° and/or HLR less than 0.80 (n = 53), there were no differences between the CC and C-only grafting techniques for radiographic and clinical outcomes, QuickDASH scores, and malunion rate. In patients who had preoperative LISA greater than 70° and/or HLR greater than 0.80 (n = 45), radiographic outcome measures, range of motion, and QuickDASH scores were significantly better in the CC than in the C-only group. Scaphoid malunion was observed in 9 of 22 of C-only patients (41%) and 4 of 23 of CC patients (18%).

CONCLUSIONS

The severity of the scaphoid deformity may be a factor in determining the best graft type, because this may affect the rate of successful deformity correction. Corticocancellous grafting in patients who had a high degree of scaphoid deformity provided consistent deformity correction and superior QuickDASH scores. Otherwise, C-only grafting provides earlier time to union and equivalent clinical and radiographic outcomes compared with CC grafting.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic I.

[Osteophyte-induced impingement reduces range of motion in humpback deformity of incorrectly healed scaphoid reconstruction]

BACKGROUND

The gold standard in the treatment of scaphoid pseudarthrosis is reduction, interposition of an iliac crest graft and stabilization with a headless bone (Herbert) screw, aiming to reduce the frequently observed humpback deformity. This study correlated the extent of humpback deformity after scaphoid reconstruction to clinical and radiological postoperative parameters.

MATERIAL AND METHODS

Between 2008 and 2010 a total of 56 patients with scaphoid pseudarthrosis were surgically treated. Of the patients 34 could be included in this retrospective study. The average follow-up period was 7.3 months. The humpback deformity was evaluated by computed tomography (CT) scan performed along the long axis of the scaphoid. The disability of the arm, shoulder and hand (DASH) score, grip strength (Jamar), range of motion (RoM), Mayo wrist score (MWS) and other parameters were used to determine the clinical outcome. The patients were divided into two groups: 1) no or only slight humpback deformity (<25°), 2) severe humpback deformity (>45°).

RESULTS

The RoM and DASH scores were slightly better for the first group. The second group had a significantly increased incidence of osteophyte formation (p < 0.05) and decreased RoM (-16°).

CONCLUSION

It is postulated that the main disadvantage of an nonreduced humpback deformity is the increased occurrence of osteophyte formation in the dorsal aspect of the scaphoid. This can cause an impingement during extension and leads to a significant restriction of movement of the wrist.

LEVEL OF EVIDENCE

III.

Clinical Outcomes of Double-Screw Fixation with Autologous Bone Grafting for Unstable Scaphoid Delayed or Nonunions with Cavitary Bone Loss

Objective  This study reports on the clinical outcomes of double screw fixation with autologous cancellous bone grafting and early active range of motion for delayed and nonunited scaphoid waist fractures with cavitary segmental bone loss. Patients and Methods  Twenty-one consecutive patients underwent fixation using two 2.2 mm antegrade headless compression screws with autologous distal radius cancellous bone graft. Postoperatively, patients were allowed early active motion with a resting splint until union was achieved. Patients were reviewed radiologically and clinically to assess for fracture union, complications, residual pain, wrist function, and return to work and recreational activities. Results  All but one patient was male, and the mean age was 23 years (range, 15-38 years). The average time from initial injury was 16 months (range, 3-144 months). Nineteen of 21 (90.5%) patients achieved union at a mean of 2.8 months (range, 1.4-9.2 months). Of the patients who failed, one underwent revision surgery with vascularized bone grafting at 10.6 months. The other patient refused further intervention as he was asymptomatic. Conclusion  Double-screw fixation with bone grafting and early active range of motion is a safe and effective technique for management of delayed and nonunited unstable scaphoid fractures with cavitary bone loss. This potentially allows for earlier return to function, without compromise to union rates. Level of Evidence  This is a Level IV, retrospective case series study.

Scaphoid non-union with pre-existing screws treated by 3D preoperative planning

Scaphoid fractures, if deemed operative, can often be treated successfully by headless compression screw fixation. Unfortunately, some patients go on to develop a scaphoid fracture non-union with screw loosening, bone resorption, bone deformity and carpal malalignment. To assist surgeons in managing these difficult cases, specifically designed scaphoid fracture plates have recently been introduced. We present a case of a scaphoid fracture non-union with retained screws and bone loss that was effectively treated by volar plate fixation using a three-dimensional (3D) printed model to assist with restoration of scaphoid morphology and implant positioning. Before surgery, 3D preoperative planning using a surface registration technique and a 3D printer was performed. Referring to the 3D-printed reduced model facilitated the prediction of gaps after reduction and helped decide the implant position and screw directions. Carpal alignment parameters gradually improved by 1 year postoperatively.

[3D Imaging for the analysis of scaphoid fractures and non-unions]

The aim of the present study is to give an overview over the possibilities of 3D imaging in the analysis of scaphoid fractures and non-unions and to discuss them on the base of case studies and literature.

[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.

Understanding the Patterns of Deformity of Wrist Fractures Using Computer Analysis

Computer modeling of the wrist has followed other fields in the search for descriptive methods to understand the biomechanics of injury. Using patient-specific 3D computer models, we may better understand the biomechanics of wrist fractures in order to plan better care. We may better estimate fracture morphology and stability and evaluate surgical indications, design more adequate or effective surgical approaches and develop novel methods of therapy. The purpose of this review is to question the actual advances made in the understanding of wrist fractures using computer models.

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.

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

Purpose

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

Methods

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

Results

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

Conclusions

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

Type of study/level of evidence

Therapeutic IV.

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.

Vascularized pedicled graft from distal radius for scaphoid nonunion with double stabilization: A long term follow up study

PURPOSE

The aim of the present study is to present the long-term efficacy of the graft of the distal radius based on the 1,2 intercompartmental supraretinacular artery (1,2 ICSRA) for the treatment of scaphoid nonunion with a proposed treatment of double stabilization with Kirschner wires and external fixator.

METHODS

Between 2007 and 2013 we retrospectively reviewed 11 patients who were operated for established scaphoid nonunion with pedicled vascularized distal radius graft based on the 1,2 ICSRA in our department. Stabilization of the graft was achieved with Kirschner wires and the wrist was immobilized with a transarticular external fixator. All patients were evaluated pre- and post-operatively both clinically and radiologically. The DASH score was also completed by the patients before and after the operation. The minimum follow-up of the patients was 5 years.

RESULTS

The mean age of the patients was 28.64 years (range, 18-49 years). Ten patients were males (90.91%) and one female (9.09%). In all patients, union was achieved. The mean time of union was 11.2 weeks (range, 8-18 weeks). The mean follow-up was 61.32 months (range, 60-72 months). Compared to the contralateral hand there was noticed 14° lack in flexion and 18° in extension. The mean DASH score showed also significant improvement from 23.1 (range, 9.4-50.6) preoperatively to 4.72 (range, 0-22.8) during the last follow-up.

CONCLUSION

The 1,2 ICSRA distal radius graft consists a trustworthy pedicled vascularized graft for the treatment of nonunion presenting very promising long-term outcomes.

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.

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.

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.

Primary medial femoral condyle vascularized bone graft for scaphoid nonunions with carpal collapse and proximal pole avascular necrosis

This study aimed to determine the outcome of free vascularized medial femoral condyle bone grafts in the primary treatment of scaphoid nonunions with scaphoid foreshortening or carpal collapse and intraoperatively documented avascular necrosis. Thirty-two patients (28 male, four female) met the inclusion criteria. Median time from injury to surgery was 70 weeks. Thirty of 32 patients healed at a median of 12 weeks. There was significant improvement from preoperative to postoperative lateral intrascaphoid angle, scapholunate angle, and radiolunate angle. Two scaphoids failed to unite; one patient underwent scaphoidectomy and four-corner fusion 15 months postoperatively after suffering a subsequent injury. Another patient underwent 1,2-intercompartmental supraretinacular artery-based vascularized bone grafting at 4 months postoperatively and then scaphoid excision with four-corner fusion 4 years later. The free vascularized medial femoral condyle bone graft restores scaphoid vascularity and architecture while promoting union in a subset of scaphoid nonunions that has historically been a clinical challenge. Level of evidence: IV.

Volar Vascularized Strut Graft for Avascular Scaphoid Nonunion Using the 1,2 Intercompartmental Supraretinacular Artery

In this retrospective study, we report the preliminary results of a novel technique for volar vascularized strut grafting to treat avascular scaphoid nonunion by using the 1,2 intercompartmental supraretinacular artery through a single incision. Forty-three of 45 patients with avascular scaphoid nonunion healed at a mean of 13 weeks (range, 3 to 10 mo). Complications consisted of 1 pin tract infection that resolved with oral antibiotics and 4 cases of transient dysesthesia of the radial sensory nerve. In 4 patients with equivocal radiographs, computed tomography scans confirmed bony union. The 2 patients who remained unhealed subsequently underwent proximal row carpectomy. Two other patients had persistent pain with the progression of radiocarpal arthritis. Our technique provides good results for the treatment of avascular scaphoid fracture nonunion. Notable advantages include performance through a single incision, use of an already established vascularized bone graft, volar graft placement, and no requirement for microvascular free graft reconstruction. It also provides the surgeon with the ability to adjust the procedure intraoperatively in the event of unexpected avascularity, without requiring substantially longer operative time or additional equipment.

Treatment of scaphoid waist nonunion by one, two headless compression screws or plate with or without additional extracorporeal shockwave therapy

INTRODUCTION

Scaphoid nonunion remains challenging for hand surgeons. Several treatment options are available such as: non-vascularized or vascularized bone grafting, with or without additional stabilization. In the last few decades, extracorporeal shockwave therapy (ESWT) has become an established procedure for treating delayed and nonunions. Purpose of this retrospective follow-up study was (a) to investigate union rate and clinical outcome of the different implants [either one/two headless compression screws (HCS) or a plate] and (b) union rate and clinical outcome using only surgery, or a combination of surgery and ESWT.

MATERIALS AND METHODS

The study included 42 patients with scaphoid nonunions of the waist with a mean follow-up of 52 months. All patients received a non-vascularized bone graft from the iliac crest and stabilization was achieved by using one, two HCS or a plate. ESWT was performed with 3000 impulses, energy flux density per pulse 0.41 mJ/mm² within 2 weeks after surgery. Clinical assessment included range of motion (ROM), pain according to the Visual Analog Scale (VAS), grip strength, Disability of the Arm Shoulder and Hand Score, Patient-Rated Wrist Evaluation Score, Michigan Hand Outcomes Questionnaire and modified Green O'Brien (Mayo) Wrist Score. In addition, each patient had a CT scan of the wrist.

RESULTS

A total of 33/42 (79%) patients showed union at the follow-up investigation. Patients treated with additional ESWT showed bony healing in 21/26 (81%) and without ESWT in 12/16 (75%). Patients that were stabilized using one HCS showed bony healing in 6/10 (60%), with two HCS 10/12 (83%) and by plate 17/20 (85%). The ESWT group had a significantly lower pain score according to the VAS and better modified Green O'Brien (Mayo) Score. No differences could be found in respect of ROM, grip strength, functional outcome score depending of which stabilization method was used.

CONCLUSIONS

Stabilization of scaphoid waist nonunions with two HCS or plate showed higher union rates than a stabilization using only one HCS. In addition, ESWT combined with a nonvascularized bone graft from the iliac crest seems a suitable option for treating scaphoid nonunions.

The Effect of Computed Tomography Scans Oriented Along the Longitudinal Scaphoid Axis on Measurements of Deformity and Displacement in Scaphoid Fractures

PURPOSE

Reformatting computed tomography (CT) scans along the scaphoid longitudinal axis improves the ability to detect scaphoid fractures compared with reformats along the wrist axis. However, it remains unclear whether scaphoid axis reformats affect measurements of displacement or deformity, which are factors that drive the clinical decision to perform open reduction internal fixation. Our null hypothesis was that reformatting CT scans along the scaphoid axis does not affect measurements of fracture displacement and deformity.

METHODS

Thirty patients with CT scans demonstrating scaphoid fractures (4 proximal pole, 17 midwaist fractures, and 9 distal) were identified and reformatted along 2 axes: the longitudinal axis of the scaphoid and the longitudinal axis of the wrist. The reformatted scans were sent to 2 musculoskeletal radiologists and 2 orthopedic hand surgeons who made the following measurements: (1) fracture gap, (2) displacement of the articular surface, (3) intrascaphoid angle, and (4) height to length (H:L) ratio.

RESULTS

The reliability of each of the measurements cited above was compared for all raters between the 2 axes using intraclass correlation coefficients. Measurement of fracture gap and articular displacement trended toward more reliability in the wrist axis, whereas measurement of H:L ratio and intrascaphoid angle trended toward more reliability in the scaphoid axis. However, no differences in measurements between the 2 axes were statistically significant.

CONCLUSIONS

This study demonstrates that reformatting CT scans in line with the axis of the scaphoid does not result in more reliable measurements of displacement or deformity.

CLINICAL RELEVANCE

Measurements of displacement and deformity in scaphoid fractures can be made in the wrist axis with comparative reliability to those in the longitudinal scaphoid axis.

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.

Free Vascularized Medial Femoral Condyle Bone Graft After Failed Scaphoid Nonunion Surgery

BACKGROUND

Outcomes following revision surgery for scaphoid nonunions with osteonecrosis are guarded. We hypothesized that use of free vascularized medial femoral condyle (MFC) bone grafts can lead to healing of the nonunion, increase vascularity of the proximal pole, and restore scaphoid architecture, resulting in acceptable functional outcomes.

METHODS

We performed a retrospective review of 49 patients who were treated with an MFC bone graft, between May 2005 and September 2016, after prior failure of operative treatment for scaphoid nonunion. The mean time from the injury to the revision surgery with the MFC bone graft was 24 months, and the mean time from the prior, failed surgery was 15 months. Thirty-six of the 49 patients had had a prior bone graft procedure and 6 patients had had 2 previous surgical procedures for the nonunion. The initial internal fixation of the scaphoid fracture was with a scaphoid screw in 43 patients. All patients had documented osteonecrosis of the proximal pole at the time of our surgery. Carpal indices, time to union, pain scores, functional outcomes, and complications were recorded.

RESULTS

Forty-one (84%) of the 49 previously operated on scaphoid nonunions healed at a mean of 16 weeks (range, 9 to 31 weeks) after the MFC bone-grafting as confirmed on computed tomography (CT). Radiographs demonstrated significant improvement in carpal alignment following the surgery with the MFC bone graft. Comparison between preoperative and postoperative values showed a trend toward improved grip strength and no important change in total wrist range of motion. Subsequent procedures were performed in 29 patients, 21 of whom had planned Kirschner wire removal. All 24 patients in whom scaphoid union had been achieved and who were available for follow-up were able to work or attend school full-time, and 88% were satisfied or very satisfied with their wrist function. Age, smoking status, body mass index, time to surgery, and preoperative radiographic findings were not found to be significant predictors of failure.

CONCLUSIONS

MFC grafts increase vascularity and restore scaphoid architecture, promoting union in most patients with the combination of proximal pole osteonecrosis, carpal collapse, and failed prior scaphoid nonunion surgery.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

The clinical result of arthroscopic bone grafting and percutaneous K-wires fixation for management of scaphoid nonunions

The purpose of this study is to analyze the clinical results of patients with scaphoid nonunion treated with arthroscopic bone grafting and K (Kirschner)-wires fixation.We retrospectively reviewed the records of 27 patients with scaphoid nonunion who had been treated with arthroscopic bone grafting and K-wires fixation method from November 2008 to February 2014. The average patient age was 35 years. The time from injury to treatment averaged 45 months. The average follow-up period was 18 months. Bone union was assessed using serial plain radiographs. The functional outcome was evaluated by comparing the modified Mayo wrist score with the visual analog scale (VAS) for pain, which were measured at the time of preoperation and at final follow-up.Union was achieved in 26 of the 27 nonunions (96.29%). The average radiologic union time was 10 weeks. The average VAS score decreased from 6.38 (range, 3-10) preoperatively to 1.59 (range, 0-3) at the final follow-up. The average modified Mayo wrist score improved from 60.19 preoperatively to 83.46 at the final follow-up. According to this score, there were 12 excellent, 6 good, and 9 fair results at the final follow-up.Arthroscopic bone grafting and percutaneous K-wires fixation is an effective treatment method for a scaphoid nonunion and has the advantages of allowing thorough assessment, enabling a comprehensive management approach for scaphoid nonunion in a minimally invasive manner, and this method can also be used for the scaphoid nonunion with SNAC stage I.

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.

Corticocancellous bone graft vs cancellous bone graft for the management of unstable scaphoid nonunion

INTRODUCTION

This study was undertaken to determine whether corticocancellous bone grafting and cancellous bone grafting differ in terms of bone union rate, restoration of scaphoid anatomy, and wrist function when unstable scaphoid nonunions are concomitantly treated by screw fixation.

MATERIALS AND METHODS

This is retrospective cohort study. In Group A (17 patients), unstable scaphoid nonunion was treated with corticocancellous graft harvested from the iliac crest and headless compression screw using volar approach. In Group B (18 patients), unstable scaphoid nonunion was treated with cancellous graft harvested from the distal radius or iliac crest and headless compression screw using volar approach Mean time to union was measured using CT image. Scaphoid deformity was also measured using lateral intrascaphoid angle and height to length ratio using CT images. Wrist functional status was assessed by measuring grip strength, wrist range of motion, and DASH score at 1 year postoperatively.

RESULTS

Mean time to union was significantly greater in Group A (15 weeks vs. 11 weeks). No significant intergroup difference was observed for lateral intrascaphoid angle and height to length ratio after treatment of scaphoid nonunion. No significant intergroup difference was observed for grip strength, wrist range of motion, or DASH scores at 1 year postoperatively.

CONCLUSIONS

Cancellous bone grafting was found to lead to earlier bone union than corticocancellous bone grafting and to similar restorations of scaphoid deformity and wrist function when scaphoid nonunion was treated by headless compression screw fixation and bone grafting.

LEVEL OF EVIDENCE

Prognostic, III.

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.

Stabilization of scaphoid type B2 fractures with one or two headless compression screws

INTRODUCTION

Fractures of the scaphoid account for the most commonly injured carpal bone. Minimally displaced fractures of the waist will heal in 85-90% when using a below elbow cast. However, fractures with displacement have a higher risk for nonunion. Therefore, open reduction and fixation with headless compression screws (HCS) have become the preferred method of treatment. The aim of this study was to compare the radiological and clinical outcome of unstable scaphoid B2 type fractures, stabilized using one or two headless compression screws.

PATIENTS AND METHODS

A total of 47 unstable scaphoid B2 type fractures were included in this retrospective follow-up study. Twelve patients were not accessable and three refused to attend follow-up checks. Therefore, a total of 32 patients were included in this study with a mean follow-up interval of 43 (12-81) months. Twenty-two patients were treated using one HCS and ten with two HCS. Clinical assessment included range of motion (ROM), pain according to the visual analogue scale (VAS), grip strength, Disability of the Arm, Shoulder and Hand Score, Patient-Rated Wrist Evaluation Score, Michigan Hand Outcomes Questionnaire and modified Green O'Brien Wrist Score. The follow-up study on each patient included a CT-Scan of the wrist which was analyzed for union, osteoarthritis, dorsiflexed intercalated segment instability and humpback deformity.

RESULTS

Radiologically, 29/32 (91%) of the scaphoid B2 type fractures showed union, 10/10 (100%) in the two HCS group and 19/22 (86%) in the one HCS group (p < 0.05). No significant differences could be found in respect to ROM, grip strength, VAS and scores between the groups. Screw removal was necessary in two patients in the two HCS group and one in the one HCS group.

CONCLUSION

The unstable B2 type fractures of the scaphoid, when using two HCS without bone grafting is a safe method, shows a significantly higher union rate and equal clinical outcome compared to stabilization using only one HCS.

Treatment of Scaphoid Fractures: European Approaches

Scaphoid fractures account for 2% of all fractures. In Europe, the incidence is 12.4/100,000/y. This article focuses on the European perspective on understanding and management of these injuries. These fractures occur in young, active patients. The aim of treatment is union. Osteoarthritis is almost inevitable if the fracture does not unite. Cast immobilization is the treatment of choice in occult or stable fractures with 90% to 95% healing. Acute/primary surgery may be considered in some patients. The European literature stresses the importance of taking the patient's wishes into consideration after careful counseling about alternative treatment methods.

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.

Long-Term Outcomes of Scaphoid Malunion

Background: The optimal treatment of patients with a scaphoid malunion remains controversial. The long-term outcomes of operative and nonoperative management have not been established. Methods: We conducted a retrospective review of the outcomes of all scaphoid malunions treated at single institution over a 30-year period. This included patients who underwent corrective osteotomy, salvage procedures (ie, dorsal cheilectomy, radial styloidectomy, and scaphoidectomy with midcarpal fusion), and those who refused operative intervention. The Mayo Wrist Score was determined at the time of surgical evaluation. Patient-Rated Wrist Evaluation (PRWE) and Disabilities of the Arm, Shoulder and Hand (QuickDASH) surveys were sent to all patients for long-term follow-up. Results: Seventeen patients had follow-up at a mean 21.4 years (range, 12-30 years). The mean initial lateral intrascaphoid angle was 58°. Of the 17 patients, 11 proceeded with surgery and 6 opted for nonoperative management. A corrective osteotomy was performed in 4 patients. Of the remaining 7 surgical patients, 5 patients underwent procedures such as cheilectomy and radial styloidectomy, whereas 2 patients had a scaphoidectomy with midcarpal fusion. The final mean PRWE and QuickDASH scores for corrective osteotomy, salvage procedures, and nonoperative treatment were 23 and 6, 18 and 10, and 33 and 22, respectively. Conclusion: Long-term outcomes were similar between operative and nonoperative management.

Is Casting for Non-Displaced Simple Scaphoid Waist Fracture Effective? A CT Based Assessment of Union

OBJECTIVE

The purpose of this study is to report the union rate and time to union for acute non-displaced scaphoid waist fractures treated with a short arm thumb spica cast.

METHODS

A database was searched (2006-2013) to identify acute undisplaced scaphoid waist fractures. Cases that were not given a trial of casting were excluded (n=33). X-rays, CT scans and health records for each patient were reviewed to extract data.

RESULTS

172 patients met inclusion criteria. There were 138 males, 34 females, the mean age was 30 ± 16 years. The union rate was 99.4% (1 nonunion/172 subjects). The mean time to union was approximately 7.5 weeks (53 ± 37 days). Energy of injury, age or gender did not affect union rates or time to union. Cysts did not affect the union rate (p=0.73) but patients with cystic resorption along the fracture line required approximately 10 weeks for union (69 ± 60 days) compared to 7 weeks (51 ± 34 days) for those without cysts (p=0.05). Diabetes did not affect the union rate (p=0.81) but was found to increase the risk of delayed union (p=0.05). There was a weak, but statistically significant correlation between the number of days before the fracture was casted and the length of time needed to achieve union (r=0.27, p=0.001).

CONCLUSION

Non-displaced scaphoid waist fractures have a high healing rate with appropriate identification and immobilization. Follow-up CT scans to assess healing can identify union within a shorter time frame (~7 weeks) than previously reported in the literature.

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.