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.     

Treatment of scaphoid fractures and nonunions

Scaphoid fractures are common but present unique challenges because of the particular geometry of the fractures and the tenuous vascular pattern of the scaphoid. Delays in diagnosis and inadequate treatment for acute scaphoid fractures can lead to nonunions and subsequent degenerative wrist arthritis. Improvements in diagnosis, surgical treatment, and implant materials have encouraged a trend toward early internal fixation, even for nondisplaced scaphoid fractures that could potentially be treated nonoperatively. Despite the advent of newly developed fixation techniques, including open and percutaneous fixation, the nonunion rate for scaphoid fractures remains as high as 10% after surgical treatment. Scaphoid nonunions can present with or without avascular necrosis of the proximal pole and may show a humpback deformity on the radiograph. If left untreated, scaphoid nonunions can progress to carpal collapse and degenerative arthritis. Surgical treatment is directed at correcting the deformity with open reduction and internal fixation with bone grafting. Recently, vascularized bone grafts have gained popularity in the treatment of scaphoid nonunions, particularly in cases with avascular necrosis. This article reviews current concepts regarding the treatment of scaphoid fractures and nonunions.     

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.     

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.     

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.     

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.     

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.     

The outcomes and complications of 1,2-intercompartmental supraretinacular artery pedicled vascularized bone grafting of scaphoid nonunions

PURPOSE: Over the past decade vascularized bone grafts that use a 1,2-intercompartmental supraretinacular artery (1,2-ICSRA) pedicle have gained popularity in the treatment of scaphoid nonunions. The purpose of this study was to evaluate critically the outcome, complications, and failures of 1,2-ICSRA-based vascularized bone grafting at our institution to understand better the appropriate indications, methods, and possible contraindications. METHODS: From January 1994 through July 2003, 50 scaphoid nonunions in 49 patients were treated with 1,2-ICSRA-based vascularized bone grafts. A retrospective review of the clinical and radiographic information was performed. Two patients were lost to follow-up study. Nine female and 38 male patients averaging 24 years of age were followed-up for an average of 7.8 months. RESULTS: Thirty-four scaphoid nonunions went on to union at an average of 15.6 weeks after surgery. Complications occurred in 8 patients and consisted of graft extrusion, superficial infection, deep infection, and failure of fixation. Univariate risk factors for failure included older age, proximal pole avascular necrosis, preoperative humpback deformity, nonscrew fixation, tobacco use, and female gender. CONCLUSIONS: Although previous researchers have concluded that vascularized bone grafts based on the 1,2-ICSRA are efficacious in the treatment of scaphoid nonunions, we determined that a successful outcome is not universal and depends on careful patient and fracture selection and appropriate surgical techniques. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic, Level IV.     

Use of the 1,2 intercompartmental supraretinacular artery as a vascularized pedicle bone graft for difficult scaphoid nonunion

Fourteen patients with established scaphoid nonunion were treated with vascularized pedicle bone grafting. All nonunions healed at a mean of 11.1 weeks (range, 8-16 weeks). Wrist motion was minimally affected by surgery. Intercarpal and scaphoid angles were improved after surgery, particularly in patients with preoperative humpback deformity who had previous interposition grafting. Outcome, based on a self-assessment questionnaire administered at a mean 30 months of follow-up (range, 19-53 months), showed 2 excellent, 7 good, 4 fair, and 1 poor result. Three patients showed progressive radioscaphoid arthrosis. Vascularized bone grafts are indicated in proximal pole fracture nonunions, in the presence of avascular necrosis, and after conventional grafts. Radiocarpal arthritis, if present before surgery, is a poor prognostic sign.     

Scaphoid fractures. Problems associated with nonunion and avascular necrosis

This article describes the rationale for different treatment methods of scaphoid nonunions and the management of avascular necrosis.     

Vascularized bone grafts from the distal radius for disorders of the carpus

Vascularized bone grafts offer several distinct advantages over conventional, nonvascularized autografts. Because cell viability and structural integrity is maintained, primary bone healing may occur, rather than creeping substitution of necrotic bone. Cortical osteocyte viability is significantly higher than in nonvascularized grafts, approaching 90% of normal controls. Minimal bone necrosis results in less remodeling, maintained bone mass, and diminished osteopenia after transfer. Vascularized grafts also exhibit superior material properties including strength, toughness, and elastic modulus 2 to 4 times greater than conventional structural grafts. Revascularization and remodeling of adjacent avascular bone also is facilitated by living grafts. All of these properties make them attractive for treatment of some scaphoid nonunions as well as carpal avascular necrosis. The principles, anatomy, application, experimental, and clinical studies of carpal vascularized pedicled bone grafts are the focus of this article. Copyright © 2002 by the American Society for Surgery of the Hand     

Use of the Medial Femoral Condyle Vascularized Bone Flap in Traumatic Avascular Necrosis of the Navicular: A Case Report

The medial femoral condyle vascularized bone flap has a high success rate in published literature regarding its use in nonunions and avascular necrosis of the upper and lower extremities. It is reported to have minimal donor site morbidity and the ability to provide structural support and torsional strength to load-bearing areas. The flap has found particular success in the treatment of scaphoid nonunions. The tarsal navicular, similar to the scaphoid, is largely articular cancellous bone with little surface area for vascular inflow. These anatomic features make the navicular prone to nonunion and avascular necrosis in traumatic scenarios. We describe a case of nonunion and avascular necrosis of the tarsal navicular occurring as sequelae of a high-impact midfoot injury sustained in an automobile accident. After an initial attempt at open reduction and internal fixation with midfoot bridge plating, subsidence and nonunion resulted. An attempt at arthrodesis of the talonavicular and naviculocuneiform joints was then undertaken. This too failed, leading to the development of additional collapse and avascular necrosis. The site was treated with a medial femoral condyle vascularized bone flap. In this single case, the patient returned to pain-free ambulation and reported excellent outcomes and functional capacity. Although we present a successful case, a larger case series is necessary to establish the use of this flap as a reliable option for the treatment of nonunion and avascular necrosis of the tarsal navicular.     

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.     

Management of scaphoid nonunions

Scaphoid nonunions can exist with or without avascular necrosis of the proximal pole, and waist fractures may have an associated humpback deformity. CT best shows the deformity and bone loss, whereas MRI will show avascular necrosis. Operative treatment should be directed at correcting the deformity with open reduction and internal fixation and bone grafting. Vascularized bone grafts should be used in cases of avascular necrosis.     

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.     

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.     

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.     

Proximal pole scaphoid fractures and nonunion

Proximal pole fractures and nonunions of the scaphoid present an extremely challenging treatment problem. Untreated, proximal pole fractures have a high rate of developing a nonunion that may lead to painful arthritis. Cast immobilization is not adequate, and surgery is recommended for the treatment of acute fractures and nonunions. The fractures are difficult to treat through a conventional volar approach, and the preferred treatment is open reduction and internal fixation using a dorsal approach with a screw that is specially designed for the scaphoid. The type of fixation implant used is important, because the end of the screw must be buried beneath the articular cartilage when the dorsal approach is used. The main blood supply of the scaphoid enters through the dorsoradial ridge of the scaphoid. By definition, proximal pole nonunions have partial ischemia or complete avascular necrosis, because the fracture line isolates the proximal pole from the perforating vessels. The definitive treatment for these fractures is a standard or vascularized bone graft, depending on the vascularity of the proximal pole of the scaphoid in addition to internal fixation via a dorsal approach. Using this treatment algorithm, the surgeon can optimize the success rate of achieving a successful scaphoid union in the shortest possible time of immobilization. Copyright © 2001 by the American Society for Surgery of the Hand     

Scaphoid Nonunion

The natural history and treatment of scaphoid fractures and subsequent nonunions have occupied a substantial portion of the orthopaedic literature. The authors examine the role of modern diagnostic tools in making an earlier diagnosis of scaphoid nonunion, in more accurately determining the displacement and angulation of the fragments, and in identifying the presence of avascular necrosis. They also consider the various available treatment modalities, including immobilization, electrical stimulation, both conventional and vascularized bone grafting, and internal fixation. Finally, a brief review of salvage procedures and the authors' preferred treatment are presented.     

Freies gefäßgestieltes Knorpel-Knochen-Transplantat bei avaskulärer Nekrose des proximalen Kahnbeinpols

The formation of a scaphoid pseudarthrosis with avascular necrosis in the area of the carpus is a The formation of a scaphoid pseudarthrosis with avascular necrosis in the area of the carpus is a dreaded complication after conservative or operative treatment of a scaphoid bone fracture, which previously often led to partial or total stiffening operations on the wrist. Vascularized bone grafts can be used to increase the bone fusion rates in the presence of scaphoid pseudarthrosis with avascular necrosis. On a note of caution, it must be mentioned, though, that such a procedure in the presence of avascular necrosis of the proximal pole with destruction of cartilage can lead to premature radiocarpal arthritis, because a friction-free gliding in the area of the proximal scaphoid pole is no longer ensured as a result of the lacking cartilage cover.We confronted these problems in a 20-year-old male patient with avascular necrosis of the proximal scaphoid bone pole and destruction of the corresponding scaphoidal cartilage cover. We transplanted a free vascularized cartilage-bone graft from the medial femoral condyle, which was adapted in form and size to the proximal scaphoid bone pole with corresponding cartilage cover and was connected to the radial vascular bundle. This novel operation technique is described in this report and appears to be a promising way of avoiding premature radiocarpal arthritis when treating scaphoid bone pseudo-arthrosis with avascular necrosis in the presence of cartilage destruction.