Supplemental graft fixation for distal radius vascularized bone graft

Vascularized bone grafts from the distal radius have been used successfully for the treatment of scaphoid nonunions. Typically, the harvested graft is secured into the scaphoid with a press-fit technique. This type of fixation may lead to graft extrusion in the early postoperative period, and thus to treatment failure. In this technical note, we describe the use of micro bone suture anchors for supplemental fixation of the vascularized bone graft into the scaphoid. It is a simple and quick technique and provides an enhanced fixation of the vascularized bone graft, which is beneficial during the early critical period of bone healing.     

Scaphoid reconstruction with vascularized bone grafts from the distal radius

The aim of the present technical report is to describe the alternative solutions for the reconstruction of scaphoid nonunions with pedicled vascularized bone grafts from the distal radius. The surgical technique for the reconstruction A. of proximal scaphoid nonunions with pedicled bone grafts (based on the 1,2 or on the 2,3 intercomparmtental arteries) or with capsular bone grafts from the dorsal distal radius and B. of waist nonunions of the scaphoid with grafts from the palmar distal radius, pedicled on the palmar carpal arch, is presented. Vascularized bone grafts from the adjacent radius are used for the treatment of scaphoid nonunions to enhance union and to revascularize a nonviable proximal pole. The most suitable graft is selected according to the location of the nonunion (at the waist or the proximal pole of the scaphoid) and to the previous procedures/scars at the wrist level.     

A capsular-based vascularized distal radius graft for proximal pole scaphoid pseudarthrosis

PURPOSE: To evaluate the clinical results of the application of a capsular-based dorsal distal radius vascularized bone graft in scaphoid proximal pole nonunions. METHODS: Thirteen patients with symptomatic nonunion at the proximal pole of the scaphoid (10 with avascular necrosis) were treated and reviewed retrospectively. The vascularized bone graft was harvested from the distal aspect of the dorsal radius and was attached to a wide distally based strip of the dorsal wrist capsule. It was inserted press-fit into a dorsal trough across the nonunion site after scaphoid fixation with a Herbert screw. RESULTS: After a mean follow-up period of 19 months 10 of the 13 nonunions (8 of the 10 with avascular necrosis) achieved solid bone union. No complications other than the 3 persistent nonunions occurred. CONCLUSIONS: Results of the use of a capsular-based vascularized bone graft from the distal radius for proximal pole scaphoid nonunions compare favorably with the results of pedicled or free vascularized grafts. It is a simple technique that eliminates the need for dissection of small-caliber pedicle or microsurgical anastomoses. No donor site morbidity was observed. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic, Level IV.     

Vascularized bone grafts for scaphoid nonunions

Scaphoid fractures that fail to unite are at risk of developing avascular necrosis and progressive structural collapse, thereby complicating attempts at revision surgical treatment. Vascularized bone grafts have demonstrated utility in promoting consolidation in the treatment of scaphoid nonunions complicated by avascular necrosis. Numerous pedicled and free vascularized grafts have been described with variable, but generally favorable, outcomes. Understanding the indications for different grafts is critical to the successful application of these techniques and grafts in the treatment of challenging scaphoid nonunions.     

Vascularized bone grafts from the palmar radius for the treatment of waist nonunions of the scaphoid

PURPOSE: With their intrinsic vascularity vascularized bone grafts provide an alternative solution to the challenging problem of scaphoid nonunions. The union rate (after imaging evaluation including magnetic resonance imaging [MRI]) and functional outcome of using vascularized bone grafts pedicled on the palmar carpal epiphyseal artery for waist nonunions of the scaphoid are reported in this prospective case series. METHODS: The technique was applied to 9 waist nonunions resulting from fractures. The mean time elapsed from the initial injury to the procedure was 22 months and the mean follow-up time was 24 months. The graft was pedicled on the artery running at the distal edge of the pronator quadratus and was inserted in the nonunion as an intercalary graft. Six patients had postoperative MRIs to evaluate fracture healing and graft incorporation. RESULTS: Union was accomplished in all cases between 6 and 12 weeks. Postoperative MRI showed the viability of the graft (contrast-enhanced images) and confirmed union and graft incorporation. Complete absence of pain was noted in all patients. The Mayo modified wrist score increased from 63 to 92 after surgery and according to this score results were excellent in 5 patients and good in 4. CONCLUSIONS: Vascularized bone grafts from the anterior radius lead to rapid union and consolidation in cases of waist nonunion. Postoperative MRI confirms viability of the graft, union, and graft incorporation. The approach is limited to the distal radius and wrist and lacks donor site morbidity. The interposition of the graft from the palmar side allows correction of the humpback deformity and patients regain carpal height, grip strength, and painless motion. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic, Level IV.     

吻合血管的腓骨近端移植修复桡骨远端骨肿瘤切除术后骨缺损

目的 评价吻合血管的腓骨近端移植修复桡骨远端骨肿瘤切除术后骨缺损的方法及治疗效果.方法 对12例桡骨远端骨肿瘤患者行桡骨远端切除,应用吻合血管的腓骨近端移植修复骨缺损并重建桡腕关节.术后对肢体功能及影像学进行评价.结果 12例患者均获随访,时间1～9年.腕关节平均活动度:掌屈30.3°±6.5°,背伸 52.1°±8.7°,尺偏 19.2°±3.6°,桡偏 12.3°±2.1°,旋前 32.1°±4.2°,旋后 21.2°±3.9°.按Enneking标准评价肢体功能:优4例,良6例,一般2例.移植腓骨均在3～6个月达到骨性愈合.5例出现不同程度的下尺桡关节分离,3例出现桡腕关节半脱位.肿瘤无复发.结论 吻合血管的腓骨近端移植是治疗桡骨远端骨肿瘤切除术后骨缺损的有效方法.     

The use of bone grafts and substitutes in the treatment of distal radius fractures

The interest in developing biomaterials to augment fracture healing continues to grow. New products promise early return to function with minimal morbidity; however, indications to use these products remain unclear. An ideal bone graft material stimulates bone healing and provides structural stability while being biocompatible, bioresorbable, easy to use, and cost-effective. This article reviews the biology of bone grafts and the clinical evidence in the use of bone graft substitutes for the treatment of distal radius fractures.     

Comparison of united and nonunited fractures of the ulnar styloid following volar-plate fixation of distal radius fractures

Introduction

The purpose of this study was to determine whether associated nonunion of ulnar styloid fracture following plate-and-screw fixation of a distal radius fracture (DRF) has any effect on wrist functional outcomes, ulnar-sided wrist pain or distal radioulnar joint (DRUJ) instability.

Materials and methods

A total of 91 consecutive patients with a DRF and an accompanying ulnar styloid fracture treated by open reduction and volar locking plate fixation were included in this study. In the first part of the analysis, the 91 study subjects were subdivided according to the presence or not of ulnar styloid union (20 and 71, respectively) by radiography at final follow-up (average 23 months). These two cohorts were compared with respect to wrist functions at 3 months postoperatively and the final follow-up visit, and ulnar-sided wrist pain and DRUJ instability at the final follow-up visit and ulnar styloid length as determined radiographically at final follow-up. In the second part of the analysis, 49 of the 91 study subjects with an ulnar styloid base fracture were subdivided according to the presence or not of ulnar styloid base fracture union (12 and 37, respectively) at final follow-up by radiography. These two groups were also compared with respect to the above-mentioned parameters.

Results

Ulnar styloid fractures united in 20 (22%) of the 91 patients at final follow-up visit (average 23 months). No significant differences were found at any time during follow-up between patients who achieved or did not achieve ulnar styloid fracture union or ulnar styloid base fracture union.

Conclusion

Ulnar styloid nonunion does not appear to affect wrist functional outcomes, ulnar-sided wrist pain or DRUJ stability, at least when a DRF is treated by open reduction and volar plate fixation.     

Effects of surgical and nonoperative treatment on wrist function of patients with distal radius fracture distal radius fracture

Purpose

To study the effects of surgical and nonoperative treatment on wrist function in patients with distal radius fracture.

Treatment of unstable distal radius fractures with cancellous allograft and external fixation

Unstable fractures of the distal radius continue to pose a challenge to the hand surgeon. Adjunctive bone grafting is often required to augment structural integrity and aid healing. Because of the risks inherent to bone autograft harvest, however, freeze-dried, irradiated cancellous bone allograft has been used to treat unstable distal radius fractures with severe metaphyseal comminution. Seventeen patients with such fractures (mean age, 70 years; 2 males and 15 females) were treated with bone allograft and external fixation with or without internal fixation. The outcome was evaluated using the modified Mayo wrist score, demonstrating 3 excellent, 8 good, 6 fair, and no poor results on follow-up examination (mean follow-up period, 23 months; range, 7-43 months). The patients were requested to return for follow-up review between 1997 and 1998. These results show that cancellous bone allograft is a useful adjunct to external fixation in the treatment of unstable distal radius fractures.     

异体骨复合人工腕关节重建桡骨远端骨巨细胞瘤切除后骨缺损

目的:评价桡骨远端骨巨细胞瘤切除后异体骨复合人工腕关节修复重建方法及效果。方法:自2000年6月~2004年6月对8例桡骨远端骨巨细胞瘤患者行瘤段切除、异体骨复合人工腕关节修复重建术,其中男5例,女3例,年龄24~52岁,平均38岁,平均随访33.2个月;按改良Campanacci影像学分级系统对骨巨细胞瘤进行分级,其中Ⅱ级5例,Ⅲ级3例,病理骨折2例;采用肌肉骨骼肿瘤学会保肢评分标准评定术后功能。结果:随访期内所有患者未发现肿瘤局部复发和远处转移;术后无明显异体骨排异反应、感染、骨吸收和骨不连;异体骨与自体骨愈合时间平均5.6个月(4.3~8.2个月);近期人工关节假体无松动、断裂及脱位等并发症;腕关节平均活动度:掌屈38°,背伸45°,桡偏15°,尺偏20°,旋前40°,旋后65°;功能评价结果:优2例,良3例,可2例,差1例。结论:异体骨复合人工腕关节对桡骨远端肿瘤切除后骨缺损的重建是一良好的选择,远期效果尚待进一步观察。     

A novel computational method for evaluating osteochondral autografts in distal radius reconstruction

Background

We describe a novel computational method for assessing the fit of an osteochondral graft. We applied our software to five normal wrist computed tomography (CT) scans to determine the fit of the scaphoid to the lunate fossa of the distal radius.

Methods

CT scans of five wrists were digitally rendered. The capitate facet of the scaphoid was fit to the lunate fossa of the distal radius using custom software based on the iterative closest point (ICP) algorithm. This approach iteratively determines the optimal position of a model surface to minimize the sum of squares of distances from all points on a target surface. The fit of the two surfaces was reported by calculating the mean residual distance (MRD) between each point on one surface and its nearest neighbor on the other.

Results

The MRD for the five subjects was found to be 0.25 mm, with 82.8–98.3 % of the articular surfaces within 0.5 mm of each other.

Conclusions

We have developed a software algorithm for comparing two articular surfaces to test fit for a proposed joint reconstruction. The software is versatile and may be applied to any bony surface to identify new graft donor sites. The fit assessment renders a richer, three-dimensional understanding of the fit of the graft as compared to traditional two-dimensional assessments.Level of Evidence: Decision analysis, Level V     

The detailed anatomy of the 1,2 intercompartmental supraretinacular artery for vascularized bone grafting of scaphoid nonunions

PURPOSE: To describe the configuration of the 1,2 intercompartmental supraretinacular artery (1,2 ICSRA), including the location of the perforators, and to discuss the clinical use of the 1,2 ICSRA for vascularized bone grafting of scaphoid nonunions. METHODS: Thirteen fresh-frozen cadaveric forearms were used to evaluate the variations in the anatomy of the 1,2 ICSRA. After injection of red latex, the 1,2 ICSRA and its perforators were characterized and measured. Pedicle length and distal reach of the transposed 1,2 ICSRA pedicle was evaluated. We noted the relationship of the 1,2 ICSRA to the dorsal scaphoid branch of the radial artery. Another 10 specimens were injected, frozen, and sectioned to evaluate vascular penetration into the dorsal distal radius. RESULTS: The 1,2 ICSRA branched from the radial artery 1.9 mm proximal to the tip of the radial styloid (range -6.3-3.2 mm), on average. The average pedicle length was 22.5 mm (range 15-31 mm), which permits its application for both dorsal and volar scaphoid. The relationship between the origin of the 1,2 ICSRA and the dorsal scaphoid branch was categorized into 3 types, including--separate, combined, and shared. The average number of perforating vessels arising from the pedicle was 5.5 (range 3-7), with an average of 2.75 (range 1-7) perforators overlying a 1 by 0.5 cm block of the distal radius bone graft. A graft located between 8-18 mm proximal to the articular surface of distal radius would incorporate the greatest numbers of perforators. The most notable vascular penetration of the distal radius was demonstrated at 10.0 mm proximal to the radial styloid. CONCLUSIONS: The detailed anatomy of the 1,2 ICSRA presented in this study may guide in planning and dissection to maximize the vascularity of a pedicled bone graft based on this vessel for the management of scaphoid nonunions.     

Outcome following distally locked volar plating for distal radius fractures with metadiaphyseal involvement

BackgroundThe surgical treatment of metadiaphyseal distal radius fractures may be difficult due to the associated articular or periarticular extension that limits standard fixation techniques. Longer distal radius volar locking plates allow stable fixation of the distal fragments while providing standard plate fixation in the proximal radius. We hypothesize that this plating technique allows adequate fixation to both the distal radius and metadiaphyseal fragments. The purpose of the study is to describe the outcomes, radiographic parameters, secondary surgeries, and complication rate with this device.MethodsA retrospective chart review was conducted on adult patients with a distal radius fracture and metadiaphyseal involvement treated with a volar, distally locked plate. All patients were followed up for radiographic union, with a mean time of 219 days (range 38–575). Fracture patterns, outcomes of range of motion, grip strength, and complications, as well as injury, post open reduction and internal fixation (ORIF), and finally, healed radiographic parameters were recorded.ResultsTwenty patients with 21 fractures were included. At union, mean radiographic parameters were the following: volar tilt of 8°, radial inclination of 27°, radial height of 14 mm, and ulnar variance of −1 mm. The mean final range of motion was 52° flexion, 50° extension, 68° pronation, and 66° supination. Complications included one infection and one plate removal. Four patients developed a nonunion requiring secondary procedures. There were no incidents of hardware failure or adhesions requiring tenolysis.ConclusionDistally locked long volar plating for metadiaphyseal distal radius fractures is a safe and effective treatment option for these complex fracture patterns allowing anatomic restoration of the radial shaft and distal radius.     

Vascularized bone blocks from the toe phalanx to solve complex intercalated defects in the fingers

PURPOSE: Vascularized bone transplants resist infection and allow rapid healing but keeping small bony segments vascularized, as needed for a finger defect, is a challenge. The purpose of this article is to present a cohort of patients with traumatic intercalated compound bony defects in the fingers that were reconstructed by a vascularized toe phalanx (or part of a phalanx) in a single stage. METHODS: Eight patients were treated with an intercalary vascularized bone graft that included a part of the proximal phalanx (3 patients), most of the middle phalanx (4 patients), or a portion of each phalanx (1 patient) of a second toe (totaling 9 bone blocks). There was an associated soft-tissue defect in each patient, an infection in 6 patients, and cartilage loss in 4 patients. The toes were pedicled on the proper digital artery (6 patients) or a segment of the first dorsal metatarsal artery (2 patients). A mean length of 12 mm of vascularized bone was transferred. The associated skin island varied from a minimum of 2 x 1 cm to a maximum of 5 x 3 cm. Bleeding from all of the bone surfaces was evidenced once the clamps were released. The homolateral digital nerve and the contralateral neurovascular pedicle of the toe were kept in place. The toe defect was treated by soft-tissue arthroplasty or arthrodesis. No toe was amputated. RESULTS: Radiologic bony union was evident at 4 to 6 weeks, except in 1 patient with an acute infection whose distal union failed to unite at 6 weeks because the infection recurred. Finger length loss averaged 3 mm. All patients returned to their preoperative occupation. CONCLUSIONS: In this group of patients the toe phalanx reliably maintained its vascularization, allowing us to solve compound osteocutaneous defects in the fingers in a single stage. Donor site morbidity was minimal.