Vascularized bone graft from the supracondylar region of the femur

Treatment of Spontaneous Osteonecrosis of the Tarsal Navicular With a Free Medial Femoral Condyle Vascularized Bone Graft: A New Approach to Managing a Difficult Problem

Adult-onset spontaneous osteonecrosis of the tarsal navicular joint, or Mueller-Weiss syndrome (MWS), is an uncommon debilitating disease characterized by a painful clinical course with progressive midfoot deformity. Treatment options include nonoperative management and/or operative intervention, including percutaneous decompression of the navicular bone, stabilization of existing structures, and cancellous bone grafting from the tibia or iliac crest. To our knowledge, there have been no reported cases of treatment of MWS with a vascularized bone graft. We report an unusual case of unilateral MWS in a 25-year-old male who failed nonoperative therapy and was successfully treated with a novel operative approach using debridement followed by a free medial femoral condyle vascularized bone graft. At 18-month follow-up, the patient demonstrated an excellent outcome with return to previous level of function, including work-related and recreational activities.

LEVEL OF EVIDENCE

Therapeutic, Level IV: Case study.

Arthroscopic reduction of comminuted intra-articular distal radius fractures with diaphyseal-metaphyseal comminution

PURPOSE

In the setting of severely comminuted diaphyseal-metaphyseal fractures of the distal radius, arthroscopic reduction of the joint surface is difficult and often results in shortening and collapse. Yet, several authors have shown the benefits of arthroscopy in articular distal radius fractures. We present a method that safely allows a combination of arthroscopic reduction and rigid fixation and describe the outcomes in a small group of patients.

METHODS

Four consecutive patients with severely comminuted diaphyseal-metaphyseal articular fractures of the distal radius were treated using the stable reference fragment technique. For all cases, we used an extra-long volar locking plate applied to the diaphysis of the radius. Preoperative computed tomography scanning was used to identify the largest articular fragment. This reference fragment was reduced and stabilized with locking pegs or screws to the volar plate under fluoroscopic guidance. The articular reduction continued arthroscopically, using the reference fragment as a guide. Once the articular reduction was complete, the comminuted metaphysis was addressed and secured to the plate.

RESULTS

All patients achieved excellent clinical and radiological results. Flexion-extension averaged 124° and pronation-supination averaged 174°. One patient showed minor signs of radiocarpal osteoarthritis on radiographs at 3 years.

CONCLUSIONS

By securing the reference fragment before addressing the metaphyseal comminution, a stable platform was created. Thus, intra-articular reduction was achieved while maintaining extra-articular alignment. Although the results were excellent, the number of cases was small.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

The use of the free vascularised bone graft for nonunion of the scaphoid: a systematic review

BACKGROUND

Fractures of the scaphoid are well known to be problematic especially when complicated by avascular necrosis, nonunion and carpal collapse. Fixation techniques have involved nonvascularised bone grafting; however, in the presence of avascular necrosis, generally poor union rates (47%) occur as identified by a meta-analysis performed by Merrell et al. The introduction of pedicled vascularised bone grafts showed further improvement; however, in the presence of carpal collapse, union rates as low as 50% have been reported by Chang et al. amongst others using the 1,2-intercompartmental supraretinacular artery pedicled graft. The difficulty lies in having a short pedicle with limited manoeuvrability to correct a humpback deformity and insert into the scaphoid cavity. Prior trauma to the soft tissues or distal radius may prohibit the use of pedicled grafts. The aim of this systematic review is to examine the published evidence for the use of free vascularised bone grafts in cases of scaphoid nonunion.

METHODS

A systematic review was performed with the following defined search strategy on MEDLINE and Google Scholar: ((scaphoid nonunion) OR scaphoid pseudarthrosis) AND bone graft. Articles were reviewed and data compiled into tables for analysis. Statistical analysis was performed with determination of descriptive statistics, and differences between the groups were calculated using categorical variables and chi-square test. A p value of 0.05 or less was considered to be statistically significant.

RESULTS

Two hundred and sixty-three articles were identified with a total of 12 articles meeting the inclusion criteria. Two hundred and forty-five cases of scaphoid nonunion were identified through the articles included in this systematic review. Fifty-six patients underwent free vascularised bone grafts from the medial femoral condyle with a 100% union rate and correction of humpback deformity, and 188 patients underwent free vascularised bone grafting from the iliac crest with an 87.7% union rate. The difference between the two similar groups was statistically significant (p = 0.006).

CONCLUSIONS

The promising data suggests that the medial femoral condylar free graft based on the descending genicular vessels can be considered in cases of proximal pole avascular necrosis and humpback deformity or in situations where other flaps are precluded or deemed unlikely to cause union.

Expanding the utility of modified vascularized femoral periosteal bone-flaps: An analysis of its form and a comparison with a conventional-bone-graft

BACKGROUND

Vascularized medial femoral condyle (MFC) corticoperiosteal bone-flap is a well-accepted technique when dealing with tissue defects or infection. Its role in refractory conditions and in the possible use for options concerning modifications of this bone-flap compared to a conventional iliac bone graft (conventional-graft) are rarely discussed.

METHODS

We reviewed 21 consecutive cases concerning alternatives with some modifications of original MFC bone-flap surgery used to treat refractory conditions with bone defects, necrosis, or infection in the extremities. We present our devised approaches for this boneflap, and especially modifications of the grafted bone (including strut bone, perforator to the vastus medialis muscle, and the use of one vascular pedicle for some bone flaps) as well as the combined use of artificial bone as hybrid bone transplantation. We also compared the clinical results of 21 cases that received a conventional-graft.

RESULTS AND CONCLUSIONS

Following flap placement, 100% of the nonunion sites healed in an average of 2 months, which was significantly shorter than 5.5 months for the conventional-graft. The results showed the expanding possibility for options with regard to the form and options of this bone-flap as well as the shortening the duration of treatment, especially at the site of an infected distal tibia, insertion of the Achilles tendon on the posterior aspect of calcaneal osteomyelitis, distal end of the clavicle, clavicle or forearm with a bone defect, small bones with refractory conditions, and a femur without implant failure. However, it was not efficient for treating a forearm without bone defect.

Outcomes of free adipofascial flaps combined with tenolysis in scarred beds

PURPOSE

To review our outcomes of transferring vascularized free adipofascial flaps used to change the local tissue conditions at the time of tenolysis in adhesion-prone beds.

METHODS

Eleven free adipofascial flaps were transplanted in 10 patients after tenolysis on the forearm (3 cases), the dorsum of the hand (5 cases), or the dorsum of the proximal phalanx (3 cases). All recipient areas had badly scarred beds, 7 of which had previously failed tenolyses. In addition to tenolysis (10) or the insertion of bridging tendon grafts (1), arthrolysis of several involved joints and bone fixation for nonunion (3 cases) were carried out simultaneously. The adipofascial flap was then wrapped around the tendons or interposed between the scarred tissue and the freed tendons. In 8 cases, the flap was the lateral arm adipofascial flap, whereas adipose flaps from the toes were used for the fingers.

RESULTS

All flaps survived without vascular crisis. In all cases, total active motion was similar to the passive motion obtained at surgery. Average Disabilities of the Arm, Shoulder, and Hand score improved from 69 to 10, and average Patient-Rated Wrist Hand Evaluation score improved from 65 to 9. Secondary surgery was needed to reduce the bulk of the flap in 3 patients. One patient required an additional procedure to obtain an optimum result.

CONCLUSIONS

Free adipofascial flaps provided satisfying results in this group of patients. The flaps should be considered when the bed is scarred or after a failed tenolysis.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Vascular bone transfer options in the foot and ankle: a retrospective review and update on strategies

BACKGROUND

The foot and ankle area has a tenuous blood supply that can easily be damaged with trauma or open exposures. The navicular and talus are susceptible to avascular necrosis, making arthrodesis difficult. In addition, in this region, large bone gaps occur as a result of avascular necrosis, trauma, or infection. Often, vascularized bone flaps are required for reconstruction or salvage.

METHODS

A retrospective review of all vascularized bone flaps to the foot and ankle performed by the senior surgeon (L.S.L) from July of 2006 to July of 2012 was performed. Twelve cases were identified (seven fibula flaps and five medial femoral condyle flaps). Indications included talus avascular necrosis with tibiotalar and subtalar arthritis (n = 8), talus avascular necrosis with tibiotalar arthritis (n = 1), navicular avascular necrosis (n = 1), talus persistent nonunion (n = 1), and a traumatic bone defect (n = 1).

RESULTS

There were no flap failures or thrombotic events. Ankle stabilization was performed with plates (n = 5), compression screws (n = 2), external fixator (n = 4), and a cast (n = 1). There were three complications requiring return to the operating room. All patients ultimately obtained union, and full weight bearing was allowed at 18.7 ± 13.6 weeks after surgery.

CONCLUSIONS

The authors have successfully used the medial femoral condyle flap and fibula flap for tibiotalar arthrodesis, pantalar arthrodesis, navicular revascularization, and persistent nonunion of the talus. The medial femoral condyle is ideal when a small segment of vascularized bone is required, but when structural support is necessary, the fibula offers a larger cortical surface area, providing more rigidity. Both flaps are valid options for foot and ankle reconstruction and salvage.

Applications of the medial femoral condyle free flap for foot and ankle reconstruction

BACKGROUND

Avascular necrosis (AVN) or persistent nonunion occurs in situations of poor vascular supply. Some specific situations that plague the foot and ankle surgeon are talus nonunion, talus AVN, navicular AVN, and failed ankle arthrodesis with bone loss. The medial femoral condyle (MFC) flap has emerged as a popular source of vascularized corticocancelous bone. We present a series of cases demonstrating the versatility of the MFC flap in complex foot and ankle pathology.

METHODS

A retrospective review was completed of all MFC flaps used in the foot and ankle over the past 5 years. Five patients were identified (average age 48). Surgical indications included talar AVN and ankle arthritis, talar nonunion, and navicular AVN. All patients had undergone conventional bone grafting techniques, which failed, prior to being treated with a MFC free flap; this series of patients did not possess significant medical comorbidities. Fixation techniques included compression screw fixation, plate osteosynthesis, or fine wire external fixation. The average follow-up was 20 months (range 8 to 40 months).

RESULTS

There was a 100% flap success rate with no returns to the operating room for thrombosis. The volume of the bone flaps was 5.6 cm(3) (range 1 cm(3) to 12 cm(3)). The average follow-up time was 20 months (range 8 to 40 months). All cases resulted in union, and full weight bearing status was achieved at a mean of 23.8 weeks (range 10 to 52 weeks) postoperatively.

CONCLUSIONS

Vascularized bone transfer in the form of the MFC free flap was a valuable method for foot and ankle reconstruction. The MFC flap provided an alternative for those defects that were smaller then 3 cm in length. In our experience, for small bone defects requiring vascularized bone, the MFC flap is currently the ideal donor location supplanting the iliac crest.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

2,3 intercompartmental supraretinacular artery pedicled vascularized bone graft for scaphoid nonunions

Scaphoid nonunion is a complex problem that may continue to exist despite conventional methods of bone grafting and internal fixation. Vascularized bone grafting has been proposed as a treatment option for scaphoid nonunions with or without avascular necrosis of the proximal pole. Zaidemberg and colleagues first introduced the dorsal distal radius graft that has gained considerable popularity in the past 2 decades. Less commonly, the 2,3 intercompartmental supraretinacular artery pedicled vascularized bone graft has been used successfully with equally promising results. It has become the graft of our choice for the treatment of scaphoid nonunions as it has a longer pedicle and is able to provide a wider arc of rotation that allows easier reach of the volar carpus. The use of rigid internal fixation with screws also permitted early wrist range of motion and shorter periods of immobilization. In this article, we describe our surgical technique of harvesting the 2,3 intercompartmental supraretinacular artery pedicled vascularized bone graft. The anatomy, indications, contraindications, and complications of treatment are also detailed.

Vascularized fibular periosteal graft: a new technique to enhance bone union in children

BACKGROUND

The periosteum in children has strong osteogenic power and is quite thick, facilitating procurement. However, it has been rarely used as a vascularized flap to enhance bone union in this age range. The purpose of this study is to assess the effectiveness of a new vascularized periosteal flap harvested from the fibula for the enhancement of bone union in the pediatric age.

METHODS

Thirteen vascularized fibular periosteal grafts were used in 12 children, mean age 12.6 years. Indications included the prevention of bone allograft-host junction nonunion and treatment of recalcitrant bone nonunion. In 9 instances, the periosteal flap was harvested as a free flap and in 4 as a pedicled flap. Serial radiographs and computed tomography scans were used to evaluate the progression of callus formation and bone healing.

RESULTS

All flaps were successful in promoting bone healing and achieving bone union in a mean time of 2.8 months for metaphyseal junctions and 7.1 months for diaphyseal ones, except for 1 case, which initially failed due to a pedicle torsion. It was then resolved with a second vascularized fibular periosteal grafts, with complete union after 5 months.

CONCLUSIONS

Transfer of a vascularized fibular periosteal flap, either pedicled or as a free flap, is an effective treatment to enhance bone union in children in biologically unfavorable scenarios. The properties of periosteal tissue in the pediatric age are unique and its use in bone union enhancement permits new reconstructive strategies in children different from those described in adults.

LEVEL OF EVIDENCE

IV.

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.

The axial stability of the femur after harvest of the medial femoral condyle corticocancellous flap: a biomechanical study of composite femur models

PURPOSE

Free bone or periosteal flaps from the medial femoral condyle are being employed for treatment of recalcitrant nonunions. When harvested in a corticocancellous fashion, these flaps have the potential to compromise the stability of the femur. This study is designed to test the axial stability of the femur after harvest of corticocancellous flaps using a standardized composite femur model.

METHODS

Corticocancellous defects of standardized width and depth (2 cm × 1 cm) were designed with increasing length (3-cm intervals extending from 3 to 24 cm) over the medial femoral condyle of five composite femur models. After harvest of each corticocancellous block, the femur was subjected to an axial force of 9100 N loaded and unloaded over one second using a Mini-Bionix load frame. During the application of force, load and deformation data were collected from the load cell and linear variable differential transducer. To determine changes in stiffness or deformation with increasing flap sizes, analysis of variance with repeated measures was used. If the main effect was found to be significant, a Tukey's test was used to determine differences between specific flap sizes.

RESULTS

There were no femur fractures in any femurs for any flap size. Deformation during load increased as the size of the flap increased (2.19 mm ± 0.062 mm for the 3-cm flap defect) to (2.33 mm ± 0.113 mm for the 24-cm flap defect). Post-hoc testing of deformation shows a statistically significant difference only between the 3-cm flap defect and the 15-cm flap defect (2.19 vs. 2.30 mm) (P = 0.002). The range of stiffness is between 4,339 and 4,697 N mm(-1) . Stiffness tends to decrease significantly (P < 0.001) with increasing flap size. Harvest of flap sizes greater or equal than 9 cm results in significantly lower stiffness compared to the 3-cm flap.

CONCLUSIONS

In this composite femur model, when stressed with supraphysiologic forces, the femur retains its axial stability even after harvest of large corticocancellous flaps from its medial aspect. Statistical significance detected in deformation and stiffness may not be clinically relevant if the femur does not fracture after flap harvest. Such was the case in this experiment. The possibility exists of safely harvesting large flaps from this donor site. Corticocancellous flaps from the medial aspect of the femur may serve as an alternative to standard flaps used in medium and large osseous reconstructions. The size of flap that can be safely raised without compromising the stability of the femur has not yet been delineated.

Vascularized bone graft pedicled on the volar carpal artery from the volar distal radius as primary procedure for scaphoid non-union

INTRODUCTION

The treatment of scaphoid non-union with non-vascularized bone graft leads to non-union in 10 to 20% of cases and up to 50% in case of proximal pole necrosis. Vascularized bone graft improves consolidation rates, but is generally restricted to secondary scaphoid non-union.

HYPOTHESIS

This study assessed the value of a primary vascularized bone graft pedicled on the transverse volar carpal artery from the volar aspect of the distal radius as donor site.

PATIENTS AND METHODS

This retrospective study included 111 cases of vascularized bone graft for scaphoid non-union as primary procedure in 73 cases and secondarily in 38. The procedures were performed through a single incision.

RESULTS

Mean delay before surgery was 25.5 and 33 months respectively, with union rates of 96% and 89.5%. Results showed improvement in both groups, but were better in primary surgery in terms of range of motion, strength, pain, function, satisfaction and return to work. There were more complications with secondary surgery.

DISCUSSION

All reports agree that union is better with vascularized bone graft. This technique performed as a day of admission surgery through a single incision under locoregional anesthesia seems feasible as a primary intervention.

Living bone allotransplants survive by surgical angiogenesis alone: development of a novel method of composite tissue allotransplantation

BACKGROUND

Segmental bone defects pose reconstructive challenges. Composite tissue allotransplantation offers a potential solution but requires long-term immunosuppression with attendant health risks. This study demonstrates a novel method of composite-tissue allotransplantation, permitting long-term drug-free survival, with use of therapeutic angiogenesis of autogenous vessels to maintain circulation.

METHODS

Ninety-three rats underwent femoral allotransplantation, isotransplantation, or allografting. Group-1 femora were transplanted across a major histocompatibility complex barrier, with microsurgical pedicle anastomoses. The contralateral saphenous artery and vein (termed the AV bundle) of the recipient animal were implanted within the medullary canal to allow development of an autogenous circulation. In Group 2, allotransplantation was also performed, but with AV bundle ligation. Group 3 bones were frozen allografts rather than composite-tissue allotransplantation femora, and Group 4 bones were isotransplants. Paired comparison allowed evaluation of AV bundle effect, bone allogenicity (isogeneic or allogeneic), and initial circulation and viability (allotransplant versus allograft). Two weeks of immunosuppression therapy maintained blood flow initially, during development of a neoangiogenic autogenous blood supply from the AV bundle in patent groups. At eighteen weeks, skin grafts from donor, recipient, and third-party rats were tested for immunocompetence and donor-specific tolerance. At twenty-one weeks, bone circulation was quantified and new bone formation was measured.

RESULTS

Final circulatory status depended on both the initial viability of the graft and the successful development of neoangiogenic circulation. Median cortical blood flow was highest in Group 1 (4.6 mL/min/100 g), intermediate in Group 4 isotransplants (0.4 mL/min/100 g), and absent in others. Capillary proliferation and new bone formation were generally highest in allotransplants (15.0%, 6.4 μm³/μm²/yr) and isotransplants with patent AV bundles (16.6%, 50.3 μm³/μm²/yr) and less in allotransplants with ligated AV bundles (4.4%, 0.0 μm³/μm²/yr) or allografts (8.1%, 24.1 μm³/μm²/yr). Donor and third-party-type skin grafts were rejected, indicating immunocompetence without donor-specific tolerance.

CONCLUSIONS

In the rat model, microvascular allogeneic bone transplantation in combination with short-term immunosuppression and AV bundle implantation creates an autogenous neoangiogenic circulation, permitting long-term allotransplant survival with measurable blood flow.