A Biomechanical Comparison of Screw and Plate Fixations for Scaphoid Fractures

Comparative analysis of cancellous graft and cortico-cancellous graft in osteosynthesis of scaphoid pseudoarthrosis with plate

INTRODUCTION

Scaphoid is the most fractured carpal bone, with a 5-10% nonunion rate. Treatment challenges include choosing the implant and graft that best corrects humpback deformity and carpal malalignment with higher chances of bony healing.

OBJECTIVE

Compare cortico-cancellous and cancellous grafts between two groups of patients treating scaphoid nonunion with locking plates using autologous bone graft and evaluate bone healing rates and radiographic, tomographic, and functional parameters before and after surgery.

METHODS

Non-randomized prospective study including 20 cases of scaphoid nonunion. Groups were divided into Group A (ten patients treated with cortico-cancellous iliac graft) and Group B (ten patients treated with cancellous iliac graft). Patients underwent pre- and postoperative radiographs, computed tomography, and functional evaluation.

RESULTS

In postoperative analysis, Group A showed a statistically significant difference in intrascaphoid angle (p = 0.002) and scapholunate angle (p = 0.011) correction when comparing the pre- and postoperative periods. Group B showed a statistically significant difference in intrascaphoid angle (p = 0.002) and scapholunate angle correction (p = 0.0018), grip strength (p = 0.002), and tip pinch strength (p = 0.001) when comparing the pre- and postoperative periods. By comparing both groups, Group B showed a statistically significant difference in intrascaphoid angle correction (p = 0.002), grip strength (p = 0.002), tip pinch strength (p = 0.002), and radial deviation (p = 0.0003). There was no statistical difference when comparing bony healing between groups.

CONCLUSION

Scaphoid nonunion treatment with a locking plate was effective, showing a high bony healing rate and improved carpal alignment in imaging tests for both graft types. However, results for intrascaphoid angle correction, grip strength, tip pinch strength, and radial deviation were better in Group B.

LEVEL OF EVIDENCE

IV, case series.

Dual Construct Fixation of the Scaphoid

Dual construct fixation has been increasingly used in complex peri-articular or peri-prosthetic long bone fractures, those with poor bone quality and in revision situations. We describe the utilisation of a screw-plate construct in the setting of a juxta-articular distal pole scaphoid fracture, review the literature and provide recommendations for future use. Level of Evidence: Level V (Therapeutic).

Scaphoid Plate Osteosynthesis in Complex Fractures and Wrist Trauma: A Case Series

Introduction Treatment of scaphoid fracture is challenging due to its unique blood supply and geometry. Traditionally, a headless compression screw is the standard treatment for unstable scaphoid fracture. Some fractures are complex, for example, comminution with bone loss. A scaphoid plate is an option in these difficult fractures providing adequate rotational stability. Aim To share our experience in using scaphoid plates in complex wrist trauma and comminuted fractures. Method and material Complex wrist trauma involving scaphoid fractures that were comminuted and multi-fragmentary fractures treated with plate osteosynthesis were retrospectively reviewed between July 2019 and September 2021. Patient demographic data, preoperative radiographs, CT scans, pain, wrist range of motion, and fracture union rate to union were reviewed. Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH®) score was recorded at 1-year postoperative follow-up.  Results Nine patients associated with complex wrist trauma were included in this case series. The mean follow-up was 2.5 years (13-30 months). The union rate was 100%. The mean arc of motion was 105° (95-110°). QuickDASH® score was 19.96 at 1-year postoperative follow-up. Four patients had good outcomes, four satisfactory, and one poor outcome. One hardware complication was observed which was the impingement of the plate proximally over the articular surface of the distal radius. Conclusion A scaphoid plate is a reliable option for treating complex and difficult fractures. It provides adequate stability, especially in comminution, bone loss, or multi-fragmentary fractures which are not amendable using other fixation methods. We recommend the expansion of plate osteosynthesis beyond scaphoid nonunion into complex wrist trauma.

Fixation Techniques for Scaphoid Nonunion

Scaphoid fractures are common injuries with high risk of nonunion. Various fixation techniques exist for managing scaphoid nonunions, including Kirschner wires, single or dual headless compression screws, combination fixation techniques, volar plating, and compressive staple fixation. The indication for each fixation technique varies depending on the patient, type of nonunion, and clinical scenario.

Volar Plating of Scaphoid Fractures: A Retrospective Case Series

BACKGROUND

The purpose of this study was to evaluate the rate of union of scaphoid fractures managed with volar plating and assess postoperative complications.

METHODS

Retrospective consecutive case series of 28 patients with scaphoid fractures, 9 acute and 19 chronic nonunions, undergoing surgical fixation with volar scaphoid plating by a single surgeon between 2013 and 2019. Patients were followed up for a minimum of 3 months with scaphoid bony union being confirmed on radiograph or computed tomography. Postoperative complications and need for plate removal were recorded.

RESULTS

Overall union rate of 96% with all 19 chronic nonunions demonstrating radiological union and 1 of 9 acute fractures not uniting and requiring revision surgery. The only postoperative complication identified was symptomatic plate impingement which necessitated plate removal in 57% of cases.

CONCLUSIONS

This case series demonstrates volar plating of scaphoid fractures can be used as an alternative technique to achieve union.

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.

Clinical outcomes of double-screw fixation with bone grafting for displaced scaphoid nonunions: A series of 21 cases

Purpose

This study reports the clinical outcomes of double-screw fixation with bone grafting for displaced scaphoid nonunions.

Patients and methods

This study was a retrospective survey. From January 2018 to December 2019, 21 patients with displaced scaphoid fractures underwent open debridement and two headless compression screw fixation with bone grafting. The preoperative and postoperative lateral intrascaphoid angle (LISA) and scapholunate angle (SLA) were recorded. Preoperative and postoperative grip strength (% of the healthy side), active range of motion (AROM), visual analogue scale (VAS), and patient-rated wrist evaluation (PRWE) scores at the final follow-up were obtained for all patients for comparison.

Results

Patients were treated for an average of 38.3 months (range 12-250) after the injury. The average time of postoperative follow-up was 30.5 months (range 24-48). All fractures achieved union at a mean of 2.7 months (range 2-4) after surgery, and 14 scaphoids of 21 patients (66.7%) healed by 8 weeks. CT scans showed no evidence of cortical penetration of either screw in all patients. There was a statistically significant improvement in AROM, grip strength, and PRWE. No complications occurred in this study, and all patients returned to work.

Conclusion

This study indicates that double-screw fixation with bone grafting is an effective technique for treating displaced scaphoid nonunions.

Excessive Derotational K-Wire Angulation Decreases Compression by Headless Compression Screw

Background  Scaphoid fracture is the most common carpal bone fracture. Open reduction internal fixation of scaphoid fractures typically undergo stabilization by a single headless compression screw (HCS). During screw insertion, a derotational Kirschner wire (K-wire) is often placed for rotational control of the near and far fragment. Questions/Purposes  The aim of this study was to determine if there is an angle of derotational K-wire placement in relation to the axis of a HCS that compromises the amount of compression generated at a fracture site by the HCS. We hypothesize that increased off-axis angle will lead to decreased compression across the fracture site. Methods  A Cellular Block 20 rigid polyurethane foam (Sawbones, Vashon, WA) scaphoid model was created to eliminate variability in bone mineral density in cadaveric bone. MiniAcutrak HCS screws (Acumed, Hillsboro, OR) were used for testing. Three conditions were tested: (1) HCS with derotational wire inserted parallel to the HCS (zero degrees off-axis); (2) HCS with derotational wire inserted 10 degrees off-axis; and (3) HCS with derotational wire inserted 20 degrees off-axis. Results  A statistically significant difference in the mean compression of the control group (56.9 N) was found between the mean compression with the derotational K-wire placed 20 degrees off-axis (15.2 N) ( p  = 0.001). Conclusions  Compression at the fracture site could be impeded by placing an excessively angulated off-axis derotation wire prior to insertion of the HCS. Clinical Relevance  Our study adds a new detail to the optimal technique of HCS placement in scaphoid fractures to improve compression and fracture union.

Scaphoid plating for recalcitrant scaphoid fractures: a systematic review

We conducted a systematic review of scaphoid plating for recalcitrant scaphoid fractures using EMBASE, Pubmed, Cochrane and MEDLINE. Thirteen studies were included. Ninety-three per cent of cases reported were male with a mean age of 27 years. Bony union was reported in eleven studies and achieved in 72% to 100% of cases. Scaphoid plates showed no significant difference in union incidence compared with headless compression screws. Mean removal incidence of plates was 21%. Postoperative flexion-extension arc was 119°. Grip strength improved by 14% postoperatively over that before surgery. There was a general improvement in patient-reported outcome measures. Eighty-six per cent of reported participants returned to their previous work. In these clinical reports, plates frequently required removal more frequently than headless compression screws.

Scaphoid Nonunion Volar Plating with Pure Nonvascularized Cancellous Autograft

Background

Surgical treatment of scaphoid nonunion has evolved over the years to include a variety of procedures and techniques involving a number of vascularized and nonvascularized bone grafting options and fixation strategies. Volar plating of scaphoid nonunions with use of pure cancellous nonvascularized autograft is a safe and effective treatment method with good functional outcomes and union rates¹.

Description

Volar plating of the scaphoid nonunion is performed via a volar approach, with debridement and reduction of the nonunion site. A nonvascularized pure cancellous bone autograft is then harvested and impacted from the distal aspect of the ipsilateral radius or the olecranon. Finally, a low-profile volar locking plate is applied for fixation².

Alternatives

There is no consensus regarding the optimal treatment of scaphoid nonunion. Headless compression screws are currently popular, and advances have been made over time to include various nonvascularized and vascularized corticocancellous grafts. The advent of plate fixation of the scaphoid has enabled the surgical treatment of nonunion to better replicate scaphoid morphology, allowing for improved biomechanical stability and optimizing the biologic milieu for healing.

Rationale

Headless compression screws, although a reasonable option for most acute scaphoid fractures, may not be the most appropriate application for nonunions. Compression, in itself, is not required for the surgical treatment of scaphoid nonunion, and can even prove detrimental by forcing the reduction into a malunion. The stability of headless compression screws must rely on a structural graft to resist the compression and create friction. The more structural the graft, however, the less biologically active it tends to be. Further, the simple placement of a metallic screw within the fracture site is counter to orthopaedic principles because it dramatically lowers the surface area available for union. Volar locking plates address the shortcoming of headless compression screws by (1) directly buttressing the deforming forces superior to headless screws^3-6; (2) utilizing the most accessible, biologically active nonvascularized bone graft, which is pure cancellous graft; (3) allowing for maximal surface area contact for union; and (4) preserving the intraosseous vascular network within the scaphoid and its vascular supply at its dorsal ridge.

Expected Outcomes

Volar scaphoid plating with cancellous bone grafting is a reliable technique with excellent union rates and favorable functional outcomes. A review of 34 patients with scaphoid nonunions with segmental defects treated with volar plates and pure cancellous autograft demonstrated 100% union as verified by computed tomography scans postoperatively¹. Average Disabilities of the Arm, Shoulder and Hand scores and grip strengths improved by final follow-up. Another series of 13 scaphoid nonunions with osteonecrosis treated with volar plating and pure cancellous autograft showed 100% union and good patient-reported and functional outcomes, despite smokers, proximal poles, and previous failed surgical procedures in the cohort². These favorable results are consistent with earlier reports of the modern plating systems; however, concerns for hardware-related complications have been elucidated over the years, including symptomatic hardware impingement⁷. This risk can be mitigated by proper surgical technique and plate placement.

Important Tips

Clear visualization of the entire volar surface of the scaphoid is crucial. Take care not to reflect too much capsule, so as to cause ulnar translation of the carpus.Thorough debridement of nonviable bone is paramount. Using a 2.0 or 3.0-mm low-speed burr with continuous irrigation can be helpful. We have had successful unions even in cases in which the remaining proximal pole was just a cortical shell and essentially a hollow vessel for graft.Err on the side of verticalization of the scaphoid, overextending and supinating the distal pole. Overstuffing the nonunion site with cancellous autograft aids in reduction and maximizes the osteoinductive and osteoconductive properties of the graft.Impaction of the graft is crucial, and the surgeon should harvest more autograft than one might initially anticipate.Secure the plate to the proximal portion of the scaphoid first. There is less room for error on the proximal portion where plate positioning is more critical.Do not cross the scaphoid "line in the sand"; to do so will result in plate impingement on the radius. Proper placement of the plate is just distal to the point at which the convex surface of the proximal pole transitions to become the concave surface of the scaphoid waist, as viewed from a volar approach.Plate modification for proximal pole fractures and nonunions: removal of the most proximal hole in the plate allows for improved fixation despite the plate itself remaining behind the scaphoid "line in the sand." In these cases, the locking screws must be directed so that they buttress the subchondral bone of each pole, especially the proximal pole.

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.

Postoperative Outcomes of Volar Plate Fixation in Cases of Scaphoid Deformity or Nonunion: A Case Series

Background  Fractures through the waist of scaphoid are a common injury, resulting in deformity or nonunion. Recently, a locking plate has been shown to fix deformity or nonunion of scaphoid, with limited observation of functional postoperative outcomes. Objectives  We present a case series of 16 patients, with the disabilities of the arm, shoulder, and hand (DASH) score evaluation in primary fixation of scaphoid fractures with humpback deformity ( n  = 11) and revision open reduction internal fixation (ORIF) for nonunion ( n  = 5), using the Medartis TriLock 1.5 scaphoid plate and bone grafting. Patients and Methods  DASH scores were obtained preoperatively and postoperatively at 3, 6, and 12 (if required) months. Patient demographics, smoking status, employment type, and grip strengths were recorded. Results  Thirteen patients attended follow-up. Union was clinically and radiologically assessed with 13 achieving union. The mean preoperative DASH score was 34.0 ( n  = 16) and at treatment completion (discharge or DNA) was 11.5 ( n  = 13), with mean reduction of 18.5 ( p  = 0.03). At treatment completion, mean reduction in DASH score of revision ORIF was 13.7 ( p  = 0.27; n  = 4), compared with 20.7 ( p  < 0.01; n  = 9) in primary fixation with plate. Conclusions  Deformity correction, reduction in DASH score, and rate of union make the plate system useful in the management of scaphoid fractures with humpback deformity and revision for nonunion. Level of Evidence  This is a Level IV study.

Volar Scaphoid Plating for Nonunion: A Multicenter Case Series Study

Background  The volar scaphoid plate from Medartis (Medartis AG, Austrasse, Basel, Switzerland) is a variable angle titanium locking plate, preformed for the volar aspect of the scaphoid. It does not have compressive capability, and may act as a bridging device. It may provide an advantage over a compression screw where the pathoanatomy is less favorable to such a device with increased rotational stability. It may act as a buttress plate for correction of humpback deformity for example. It has been used in nonunions and with vascularized grafts. Questions  Our study aims to assess the results of our patients with scaphoid nonunion treated with scaphoid volar plating over a larger number of patients. We aim to identify techniques to increase the success of plating. Methods  Patients from our cohort were retrospectively reviewed. Operations were performed by three hand fellowship trained surgeons and in two centers. Inclusion involved a scaphoid plate procedure for a nonunion of the scaphoid with a minimum of 6 months of follow-up. Exclusions were those who had less than 6 months of follow-up. Data included demographics, patient-rated wrist evaluation (PRWE), a quick disabilities of the arm, shoulder, and hand (qDASH), visual analogue score, and range and grip. Radiology was reviewed. Results  Thirty-two eligible patients were assessed. The mean age was 25 years (range 13-46), 2 were female and 15 were smokers. Mean follow-up postsurgery was 18 months. Twenty-nine of 32 patients united (90.6%) on computed tomography scan. Clinical assessment was performed in the 25 patients. The mean qDASH score was 12.5 (range 0-42) and mean PRWE was 11 (range 0-54). The mean arc of motion was 115 degrees. The mean grip strength was 39 kg compared with 41 kg on the nonoperated side. Conclusion  We postulate that the plate acts like an internal bridging device, acting over a small distance, and inherent stability of the construct with structural graft and accurate reduction prior to plating is advantageous. Potential problems include plate impingement on the volar lip of the radius, particularly when trying to plate more proximal fractures. Ideally, it is utilized for mid to distal waist fractures.

Comparative outcome analysis of internal screw fixation and Kirschner wire fixation in the treatment of scaphoid nonunion

In cases with difficult scaphoid screw placement due to small, fragile bone fragments, or transplants and insufficient space, the internal Kirschner wire fixation is a fallback option; however, controversy remains regarding its stability, safety, and outcome. Between 2001 and 2011, 95 patients were treated in our center (n = 80 with cannulated compression screws and n = 15 with Kirschner wires), and retrospectively analyzed. The outcome measurements included the analysis of patient data, union rate and analysis of functional measures, and quality of life. Bony reconstructions were performed with Vascularized Bone Grafts (VBG) based on the 1,2-Intercompartmental Supraretinacular Artery (ICSRA) , Medial Femoral Condyle (MFC)-VBG, cancellous bone, and iliac crest grafts. Bony healing and functional outcome showed no significant differences between Kirschner wire fixation and cannulated compression screws, although significantly more 1,2-ICSRA-VBG were treated with Kirschner wires. Although predominantly used as an intraoperative fallback option, our data demonstrate that Kirschner wire internal fixation can be safe and reliable, with comparable bony union rates and excellent functional outcomes.

Modified Matti-Russe technique using a "butterfly bone graft" for treatment of scaphoid non-union

Introduction

Autologous bone grafts are used to treat scaphoid non-union with shortening and humpback deformity. The superiority of internally fixed bone graft to embedded bone graft has not been clearly proven.

Methods

Retrospectively analyzed 42 cases of scaphoid waist non-union treated using the "butterfly bone graft" (modified Matti-Russe technique).

Results

Complete healing was reached by all patients, with an average time of 4.4 (SD ± 0.7) months. Mayo Wrist Score improved from and QuickDASH score significantly improved in all patients after treatment.

Conclusions

Butterfly bone graft is effective and reliable in treating scaphoid non-union with shortening and humpback deformity.

Practicability of a locking plate for difficult pathologies of the scaphoid

INTRODUCTION

Headless compressions screws are the most implanted devices for scaphoid fractures and nonunions. For cases when screw osteosynthesis is not possible, a special locking plate for scaphoid reconstruction has been developed. The purpose of this study was to evaluate the safety and practicability of this device for difficult scaphoid pathologies.

MATERIALS AND METHODS

Between March 2010 and December 2014, 20 patients (age range 16-59 years) were treated with scaphoid locking plate osteosynthesis. In 17 cases it was due to scaphoid nonunion or delayed union and in three cases to treat a complex multi-fragmentary fracture of the scaphoid. Most of the initial fractures were located either in the proximal third (n = 9) or the middle third (n = 8) of the scaphoid.

RESULTS

Mean follow-up was 14.6 ± 8.9 months (range 2-30 months). All three scaphoid fractures (100%) showed bony healing in the CT scan after 2.7 ± 0.6 months. 15 of 17 (88.2%) patients with scaphoid nonunion demonstrated bony healing in the latest CT scan at an average of 6.2 ± 8.1 months (range 2-11 months) after scaphoid reconstruction. Range of motion (extension/flexion) was 104° ± 18.4° (range 80°-150°) and about one third less than the unaffected side. The average grip strength averaged 38.2 kg on the operated side and 44.1 kg on the unaffected side after surgery. 13 plates (65%) had to be removed due to impaction of the plate or protrusion of the screws.

CONCLUSIONS

This new locking device for scaphoid reconstruction seems to be a safe, useful and reliable tool in the treatment of difficult nonunions or multi-fragmentary scaphoid fractures. The practicability is convincing and satisfying fusion rates can be accomplished. However, most patients require hardware removal. We recommend using this plate as a rescue option when a stable osteosynthesis is necessary for the healing process and screw fixation has already failed or is not possible.

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.