Free medial femoral condyle bone grafting for scaphoid nonunions with humpback deformity and proximal pole avascular necrosis

Treatment of scaphoid nonunions remains a challenging problem, especially in the setting of proximal pole avascular necrosis or humpback deformity. Conventional bone grafting techniques have demonstrated unpredictable results in the setting of collapse deformities, whereas pedicled dorsal distal radius vascularized bone grafts have recently been reported to have nearly a 50% failure rate when used in scaphoid nonunions with proximal pole nonunion. Free vascularized medial femoral condyle bone grafting is one option for the treatment of scaphoid nonunions with proximal pole avascular necrosis associated with a humpback deformity. The indications, contraindications, and technique of free vascularized medial femoral condyle bone grafting are presented for the treatment of scaphoid nonunions associated with proximal pole avascular necrosis and humpback deformities.     

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 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.     

Changing concepts in the treatment of scaphoid nonunion: vascularized bone graft based on the 1,2 intercompartmental supraretinacular artery

Scaphoid fractures are a common injury encountered by hand surgeons. Fracture union can generally be achieved with cast immobilization or open reduction and internal fixation. Occasionally, these fractures fail to heal despite proper treatment or a nonunion may result from an unrecognized fracture. Traditionally, scaphoid nonunions have been treated with autologous bone grafts from the iliac crest; however, if the proximal pole is poorly vascularized, union may be difficult to achieved. Vascularized bone grafts are an alternate technique for difficult scaphoid nonunions, particularly those with avascular necrosis of the proximal segment. A graft from the distal radius based on the 1,2-intercompartmental supraretinacular artery is an excellent option for scaphoid nonunions. This article describes the anatomy of the 1,2-ICSRA and the surgical technique of harvesting a graft based on this pedicle. Vascularized bone grafts represent a changing concept in the treatment of scaphoid nonunions and provide a powerful tool for a difficult problem. The indications for this procedure continue to increase.     

Scaphoid nonunion: treatment with a pedicled vascularized bone graft based on the 1,2 intercompartmental supraretinacular branch of the radial artery

Pedicled vascularized bone grafts (Zaidemberg's technique) were used to treat 22 established scaphoid fracture nonunions, 16 of which were found to have avascular proximal poles at surgery. After a follow-up of 1-3 years, only six (27%) of the 22 fracture nonunions had united. Only two of the 16 nonunions with avascular proximal poles united, compared with four of the six nonunions with vascular proximal poles. We conclude that this technique of pedicled vascularized bone grafting may not improve the union rate for scaphoid fracture nonunions with avascular proximal pole fragments.     

Role of conventional and vascularized bone grafts in scaphoid nonunion with avascular necrosis: A canine experimental study

The effectiveness of vascularized and conventional bone grafts in the treatment of carpal fracture nonunion with avascular necrosis was evaluated in 12 adult dogs. The proximal third of the radiocarpal bone was removed bilaterally and frozen in liquid nitrogen. Its replacement, leaving a 4-mm gap, simulated a scaphoid fracture nonunion with avascular necrosis. A dorsal radius inlay graft was placed across the gap. The graft was nonvascularized, or conventional on one side, and vascularized with a reverse-flow arteriovenous pedicle on the other. Following a healing period, quantitative assessment of bone blood flow, fracture healing, and bone remodeling was conducted. Seventy-three percent of the vascularized grafts and none of the conventional grafts healed. At 6 weeks, bone blood flow in the proximal pole was significantly higher on the side of the vascularized graft. Quantitative histomorphometry of the avascular proximal segment demonstrated significantly higher levels of fluorochrome-labeled osteoid- and osteoblast-covered trabecular surfaces on the vascularized graft side. These experimental data support the potential clinical application of pedicled reverse-flow vascularized grafts in the treatment of carpal fracture nonunions with avascular necrosis, including proximal pole scaphoid nonunions.     

Donor sites for pedicled skeletal grafts of the hand,wrist, and forearm

Pedicled bone and periosteal grafts provide successful reconstruction of skeletal problems of the distal radius, wrist, and hand. The purpose of this study was to evaluate the available alternatives and to propose the most suitable skeletal grafts for the reconstruction of the distal radius, and the carpal and hand bones. The alternative donor sites (dorsal and palmar distal radius, and metacarpals), their pedicles, and the potential coverage area in relation to specific wrist and hand pathology were determined in the cadaveric dissections. In the clinical setting, 75 pedicled grafts were used for the treatment of scaphoid nonunions (62 cases), lunate necrosis (8 cases), reconstruction of the metacarpal defects (2 cases), and wrist fusions (3 cases). All alternatives have the advantage of a single approach that may be performed under tourniquet control, from the same team. Among the available alternatives, surgeon's familiarity plays the most important role for the final selection of the graft. © 2009 Wiley‐Liss, Inc. Microsurgery, 2009.     

Pedicled vascularized bone grafts for disorders of the carpus: scaphoid nonunion and Kienbock's disease

The use of reverse-flow pedicled vascularized bone grafts from the dorsal distal radius makes it possible to transfer bone with a preserved circulation and viable osteoclasts and osteoblasts. The resultant primary bone healing without creeping substitution within the dead bone is an alternative to conventional bone grafting in aiding or accelerating healing, replacing deficient bone, and/or revascularizing ischemic bone. Recent advances in understanding the anatomy and physiology of vascularized pedicled bone grafts have increased their use in treating a variety of carpal maladies. A basic understanding of the vascular anatomy, as well as the surgical principles and experimental and clinical results of pedicled vascularized bone grafts from the dorsal distal radius, is critical to understanding the use of these grafts in the treatment of scaphoid nonunions and Kienbock's disease.     

Dorsal distal radius vascularized pedicled bone grafts for scaphoid nonunions

Fractures of the scaphoid, particularly its proximal pole, are at risk of progressing to nonunion because of the tenuous, retrograde blood supply. The overall incidence of scaphoid fractures developing nonunion ranges from 10% to 15%, whereas proximal pole fractures of the scaphoid can have up to a 30% incidence of nonunion. Avascular necrosis of these proximal pole fractures can occur in 14% to 39% of cases. Dorsal distal radius vascularized pedicled bone grafting is an alternative to conventional measures for the treatment of displaced proximal pole fractures, established nonunions, and avascular necrosis of the proximal fragment. This graft is based on the 1,2-intercompartmental supraretinacular artery, which has reliable anatomy and predictable course between the first and second extensor compartments. The graft can be harvested and inset into the prepared fracture site using a single-incision approach. The indications, contraindications, technique, and results of treatment are reviewed and detailed.     

Scaphoid nonunions. Pitfalls and pearls.

Our ability to treat scaphoid nonunions has improved dramatically. The degree of collapse and bone loss can be accurately assessed in waist fractures using sagittal images on CT scans. These nonunions require reduction and bone grafting to re-establish the normal geometry of the scaphoid. Magnetic resonance imaging helps evaluate whether or not avascular necrosis is present in the proximal pole. Because of the poor prognosis of conventional bone grafts, a vascularized bone graft is recommended as the primary treatment when AVN is present. The volar collapse of the humpback deformity is best corrected with a volar approach and the proximal pole nonunion is best approached using a dorsal approach. Nearly all proximal pole nonunions require a vascularized bone graft and all acute proximal pole fractures require open reduction and internal fixation. Using specially designed cannulated screws, the nonunions can be stabilized accurately to decrease the time to resolution of the nonunion and minimize the amount of time in a cast. Stable fixation requires that the screw fixation target the central portion of the scaphoid regardless of the type of screw design used. Using these techniques, the hand surgeon should be able to provide a reasonable prognosis for patients presenting with a scaphoid nonunion, and the treatment should result in functional range of motion, grip strength, and relief of pain.     

Operative treatment of scaphoid nonunions]

43 reconstructive procedures were performed in nonunions and malunions of the scaphoid waist. In 8 cases of proximal pole nonunions the Chacha operation was carried out. Before surgical treatment SL angles and scaphoid length were measure on radiograms, taken with both hands in neutral position. Reconstruction procedures of the scaphoid waist were implemented basing on the carpal stretch test. Five different types of scaphoid nonunions were noted, basing on the localisation of the pathology. Operative procedures were selected in close correlation to nonunion localisation: simple reconstruction, reconstruction and revascularisation on the proximal part of the waist and rerevascularisation of the proximal pole. Additionally 3 revision procedures were performed in cases of nonunion after scaphoid reconstruction. Bone healing was observed in 49 cases, including the revision procedures.     

Medial femoral condyle vascularized bone grafts for scaphoid nonunions

Free vascularized bone grafts from the medial femoral condyle provide both structural support and blood supply to promote union in the difficult subset of scaphoid nonunions complicated by humpback deformity and proximal pole avascular necrosis. These nonunions have not consistently achieved union when treated with grafts which fail to restore scaphoid geometry or vascularity. The rationale, indications, contraindications, technique and results of bone grafting scaphoid nonunions with grafts harvested from the medial femoral condyle are presented.     

Dorsal capsular-based vascularized distal radius graft for proximal pole scaphoid nonunion with avascular necrosis

BackgroundScaphoid nonunion involving the proximal pole with the presence of avascular necrosis is difficult to reconstruct. We aimed to determine the efficacy of surgical treatment of proximal pole scaphoid nonunion with avascular necrosis using a dorsal capsular-based vascularized distal radius graft.MethodsBetween 2000 and 2018, 64 patients with established proximal pole scaphoid nonunion with avascular necrosis were treated using a dorsal capsular-based vascularized distal radius graft. This graft was harvested from the dorsal aspect of the distal radius with its dorsal wrist capsule attachment. Fixation of the scaphoid nonunion was performed with a small cannulated screw, followed by insertion of the vascularized graft into the dorsal trough at the scaphoid nonunion site. In the last 47 patients of this series, a micro suture anchor was placed into the scaphoid to augment graft fixation.ResultsUnion rate was 86% (55 of 64 scaphoid nonunions with avascular necrosis) at a mean time of 12 weeks. Persistent non-union was noted in eight patients and fibrous union in one patient. No patients developed donor site morbidity. No graft dislodgment was noted. There was significant improvement of the wrist functional outcomes at the final follow up.ConclusionsThe dorsal capsular-based vascularized distal radius graft is a safe and effective treatment in patients with scaphoid nonunion with avascular necrosis of the proximal pole. This pedicle vascularized bone graft is derived from a location that can easily reach the proximal third of the scaphoid avoiding microsurgical dissection or anastomosis.     

Management of scaphoid nonunions with vascularized bone grafts from the distal radius: mid- to long-term follow-up

Scaphoid nonunion represents a challenging problem that leads to disability if neglected. Vascularized bone grafts are proposed to augment the local biology and increase the likelihood of union but long-term outcomes are sparse. In this work, we present the mid- to long-term outcome of 140 scaphoid nonunions managed with vascularized bone grafts from the distal radius. Sixteen patients underwent concomitant closed wedge osteotomy of the distal radius because of arthritic changes. There were 130 males and ten females, with mean time from injury to surgery 3.3 years. Delayed presentation was associated with arthritic changes. Forty-two patients had avascular necrosis of the proximal pole and sixteen had more severe arthritic changes. The mean follow-up was 10 years. Pain decreased postoperatively but range of motion did not improve but only in early reconstructions. Grip strength reached 79% of the non-injured hand. Mayo modified wrist score improved from 56 to 84 (p < 0.001). Except one, all the rest 139 nonunions healed in a mean time of 9 weeks. MRI evaluation in 77 patients revealed healing at a mean of 3 months postoperatively even in cases of avascular necrosis. Scaphoid length, carpal height, and scapholunate angle increased, but capitolunate did not change significantly. The presence of arthritis preoperatively was associated with progression of arthritic changes after 10 years. Treatment of scaphoid nonunions with vascularized bone grafts from distal radius reliably led to highest rate of bone healing with good mid- to long-term outcomes. Enhancement of the local biology and reconstitution of scaphoid and carpal height resulted in improved function mostly in early interventions.     

Management of scaphoid nonunions

Scaphoid nonunions result in a predictable pattern of wrist arthrosis. To minimize the incidence of arthrosis, the goal of treatment should be consolidation of the fracture with the scaphoid in anatomic alignment. Computed tomography and magnetic resonance imaging scans can aid evaluation of carpal collapse, scaphoid collapse, scaphoid nonunion, bone loss, and detection of osteonecrosis. Nonunion of the scaphoid waist may result in a humpback deformity, increasing the chances of further collapse and arthrosis. This collapse deformity must be approached volarly with an intercalary bone graft and internal fixation. A dorsal approach to proximal scaphoid nonunions allows easier access for removing the necrotic bone from the proximal pole and applying accurate screw or pin fixation. Vascularized bone graft is recommended to manage scaphoid nonunions with osteonecrosis.     

以第一、二伸肌腱鞘支持带上动脉为血管蒂的桡骨瓣治疗舟骨骨不连

目的 探讨以第一、二伸肌腱鞘支持带上动脉(1,2 ICSRA)为血管蒂的桡骨瓣带蒂逆行转移治疗舟骨骨不连的手术指征、技术和疗效.方法 2007年2月至2010年10月,我科对15例舟骨骨不连患者,应用以1,2 ICSRA为血管蒂的桡骨瓣远端蒂转移植骨内固定进行治疗.其中腰部骨不连9例,近端骨不连6例.9例伴有近端骨折块缺血性坏死;3例伴有舟状骨弓背畸形及嵌入体背伸不稳(DISI);2例伴有桡骨茎突关节炎表现.所有病例均采用腕桡侧纵形切口,13例予以交叉克氏针内固定,2例行单枚Herbert螺钉附加1枚克氏针固定.12例将带血管蒂植骨块从舟骨背侧嵌插植入,3例将植骨块楔形修整后自舟骨掌侧植入.术后随访骨折愈合时间、腕痛、腕关节活动度及握力等情况.结果 术后随访时间为6～ 21个月,平均13个月,2例失访.所有随访病例X线片显示舟骨均获得骨性愈合,平均愈合时间为14.2周.所有患者腕痛消失,腕关节屈曲(59.92±4.82)°,背伸(49.73±4.58)°.根据改良的Mayo腕关节功能评分标准评定:优9例,良2例,可2例;优良率为84.6％.结论 以1,2 ICSRA为血管蒂的桡骨瓣逆行转移植骨手术,能促进舟骨骨不连的愈合,特别对有近端骨块缺血性坏死的患者疗效显著.     

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.     

Palmar lunate dislocation with a dorsal scaphoid fracture variant

A 20-year-old man had a dorsally displaced fracture of the proximal pole of the scaphoid and an ipsilateral palmar lunate dislocation--a rare combination of injuries that has not been previously reported. The most likely pathomechanics of this injury is a sheer fracture of the proximal pole of the scaphoid by the dorsal lip of the distal radius as the injury shifts from a dorsal perilunate to a palmar lunate pattern.     

Vascularised bone graft for the treatment of non-union of the scaphoid.

A 4/5 compartment pedicled vascularised bone graft from the distal radius combined with internal fixation with a Herbert type cannulated screw was used to treat non-union fractures of the proximal pole of the scaphoid in 13 patients. Non-union was identified on plain radiographs alone. Uneventful clinical and radiological healing was achieved in 11 patients. One patient had progressive signs of failure of the fixation of the screw at the proximal pole; the screw was changed and the fracture was stable at reoperation. One patient had a fall postoperatively, radiographs taken at follow-ups showed only partial healing, and he had a bone graft 12 months later. Twelve patients had clinical and radiological union of the fracture, and one patient fibrous healing alone. The technique may improve healing of non-union of fractures of the proximal pole of the scaphoid, but it is still a technical challenge.