Bishop, Allen T.

Background: The medial femoral condyle free vascularized bone flap is a valuable alternative to other types of vascularized bone grafts. The donor-site morbidity and functional outcomes after flap harvest have not been fully appreciated. The authors report the postoperative outcomes and analyze the impact of increasing the size of the flap on knee donor-site morbidity. Methods: A retrospective chart review of patients who underwent medial femoral condyle flap surgery between 2001 and 2012 at their institution was performed. The size of the flap was stratified, based on the largest dimension, into three groups. Demographics, outcomes, and complications related to the flap donor site were recorded and analyzed. Subsequently, functional status was assessed by administering a validated condition-specific measure. A univariate logistic regression analysis was performed, and results were analyzed. Results: A total of 75 patients were identified. Average age was 29.5 ± 15.2 years. Average follow-up time was 13 months. The overall complication rate was 18.6 percent. Paresthesia in the saphenous nerve distribution was the most common complication. Increasing the size of the flap resulted in a significant elevation in complication risk (p < 0.05). A total of 47 patients completed the Lower Extremity Functional Scale questionnaire. The average Lower Extremity Functional Scale score was 72.12 ± 14.18. Fifty-one percent (n = 24) scored 80 points, indicating a normal level of function on average. Conclusions: The medial femoral condyle flap has overall acceptable donor-site morbidity, with a good level of function postoperatively. Larger flaps are associated with a greater number of complications. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Background: Outcomes following revision surgery for scaphoid nonunions with osteonecrosis are guarded. We hypothesized that use of free vascularized medial femoral condyle (MFC) bone grafts can lead to healing of the nonunion, increase vascularity of the proximal pole, and restore scaphoid architecture, resulting in acceptable functional outcomes. Methods: We performed a retrospective review of 49 patients who were treated with an MFC bone graft, between May 2005 and September 2016, after prior failure of operative treatment for scaphoid nonunion. The mean time from the injury to the revision surgery with the MFC bone graft was 24 months, and the mean time from the prior, failed surgery was 15 months. Thirty-six of the 49 patients had had a prior bone graft procedure and 6 patients had had 2 previous surgical procedures for the nonunion. The initial internal fixation of the scaphoid fracture was with a scaphoid screw in 43 patients. All patients had documented osteonecrosis of the proximal pole at the time of our surgery. Carpal indices, time to union, pain scores, functional outcomes, and complications were recorded. Results: Forty-one (84%) of the 49 previously operated on scaphoid nonunions healed at a mean of 16 weeks (range, 9 to 31 weeks) after the MFC bone-grafting as confirmed on computed tomography (CT). Radiographs demonstrated significant improvement in carpal alignment following the surgery with the MFC bone graft. Comparison between preoperative and postoperative values showed a trend toward improved grip strength and no important change in total wrist range of motion. Subsequent procedures were performed in 29 patients, 21 of whom had planned Kirschner wire removal. All 24 patients in whom scaphoid union had been achieved and who were available for follow-up were able to work or attend school full-time, and 88% were satisfied or very satisfied with their wrist function. Age, smoking status, body mass index, time to surgery, and preoperative radiographic findings were not found to be significant predictors of failure. Conclusions: MFC grafts increase vascularity and restore scaphoid architecture, promoting union in most patients with the combination of proximal pole osteonecrosis, carpal collapse, and failed prior scaphoid nonunion surgery. Level of Evidence: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

This study aimed to determine the outcome of free vascularized medial femoral condyle bone grafts in the primary treatment of scaphoid nonunions with scaphoid foreshortening or carpal collapse and intraoperatively documented avascular necrosis. Thirty-two patients (28 male, four female) met the inclusion criteria. Median time from injury to surgery was 70 weeks. Thirty of 32 patients healed at a median of 12 weeks. There was significant improvement from preoperative to postoperative lateral intrascaphoid angle, scapholunate angle, and radiolunate angle. Two scaphoids failed to unite; one patient underwent scaphoidectomy and four-corner fusion 15 months postoperatively after suffering a subsequent injury. Another patient underwent 1,2-intercompartmental supraretinacular artery-based vascularized bone grafting at 4 months postoperatively and then scaphoid excision with four-corner fusion 4 years later. The free vascularized medial femoral condyle bone graft restores scaphoid vascularity and architecture while promoting union in a subset of scaphoid nonunions that has historically been a clinical challenge. Level of evidence: IV

Background: Traumatic brachial plexus injury (BPI) in patients with complete spinal cord injury (SCI) such as paraplegia or tetraplegia is a very rare and debilitating combined injury that can occur in high-energy traumas. Management of a BPI should be aimed at regaining strength for self-transfers and activities of daily living to restore independence. However, brachial plexus reconstruction (BPR) in this unique patient population requires considerable planning due to the combined elements of upper and lower motor neuron injuries. Methods: We present 2 cases of traumatic complete SCI with concomitant BPI with mean follow-up of 42 months after BPR. The first patient had a left C5-7 BPI with a T2 complete SCI. The second patient sustained a left C5-8 BPI with complete SCI at C8. Results: The first patient underwent BPR including free functioning muscle, intra- and extraplexal nerve transfers, and tendon transfers resulting in active elbow flexion and active elbow, finger, and thumb extension, but no recovery of shoulder function. While the second patient underwent extra-plexal nerve transfer to restore elbow flexion yet did not recover any function in the left upper extreimty. Conclusions: Because extensive upper and lower motor neuron injuries are present in these combined injuries, treatment strategies are limited. Expectations should be tempered in these patients as traditional methods to reconstruct the brachial plexus may result in less than ideal functional outcomes due to the associated upper motor neuron injury.

Background: The addition of adipose-derived mesenchymal stromal cells to decellularized nerve allografts may improve outcomes of nerve reconstruction. Prior techniques used for cell seeding are traumatic to both the mesenchymal stromal cells and nerve graft. An adequate, reliable, and validated cell seeding technique is an essential step for evaluating the translational utility of mesenchymal stromal cell–enhanced decellularized nerve grafts. The purpose of this study was to develop a simple seeding strategy with an optimal seeding duration. Methods: A dynamic bioreactor was used to seed rat and human mesenchymal stromal cells separately onto rat and human decellularized nerve allografts. Cell viability was evaluated by MTS assays and cellular topology after seeding was determined by scanning electron microscopy. Cell density and distribution were determined by Live/Dead assays and Hoechst staining at four different time points (6, 12, 24, and 72 hours). The validity and reliability of the seeding method were calculated. Results: Cells remained viable at all time points, and mesenchymal stromal cells exhibited exponential growth in the first 12 hours of seeding. Seeding efficiency increased significantly from 79.5 percent at 6 hours to 89.2 percent after 12 hours of seeding (p = 0.004). Both intrarater reliability (r = 0.97) and interrater reliability (r = 0.92) of the technique were high. Conclusions: This study describes and validates a new method of effectively seeding decellularized nerve allografts with mesenchymal stromal cells. This method is reproducible, distributes cells homogenously over the graft, and does not traumatize the intraneural architecture of the allograft. Use of this validated seeding technique will permit critical comparison of graft outcomes.

IntroductionIn prior small animal studies, we maintained vascularized bone allotransplant viability without long‐term immunotherapy. Instead, an autogenous neoangiogenic circulation is created from implanted vessels, sufficient to maintain bone viability with only 2 weeks immunosupression. Blood flow is maintained despite rejection of the allogeneic vascular pedicle thereafter. We have previously described a large animal (swine) pre‐clinical model, reconstructing tibial defects with vascularized tibial allotransplants. In this manuscript, autologous angiogenesis is evaluated in this model and correlated with bone viability.Materials and methodsAllogeneic tibial segments were transplanted across a major swine leukocyte antigen mismatch. Microvascular repair of the bone VCA pedicle was combined with intraosseous implantation of an autogenous arteriovenous (AV) bundle. The bundle was ligated in group 1 (n = 4), and allowed to perfuse in group 2 (n = 4). Three‐drug immunotherapy was given for 2 weeks. At 16 weeks micro‐CT angiography quantified neoangiogenic vessel volume. Bone viability, rejection grade, and bone healing were analyzed.ResultsA substantial neoangiogenic circulation developed from the implanted AV‐bundle in group 2, with vessel density superior to ligated AV‐bundle controls (0.11 ± 0.05 vs. 0.01 ± 0.01, P = .029). Bone allotransplant viability was also significantly enhanced by neoangiogenesis (78.7 ± 4.4% vs. 27.7 ± 5.8%, P = .028) with higher bone healing scores (21.4 ± 2.9 vs. 12.5 ± 3.7, P = .029). Ligated control tibias demonstrated disorganized bone morphology and higher local inflammation (P = .143).ConclusionImplantation of autogenous AV bundles into vascularized bone allotransplants resulted in the rapid formation of a neoangiogenic autogenous blood supply in a swine tibia model that maintained bone viability, improved bone healing, and minimized rejection.

We studied 57 patients with isolated lunotriquetral injuries treated by arthrodesis, direct ligament repair, or ligament reconstruction. The outcomes were compared by using written questionnaires, the Disabilities of the Arm, Shoulder and Hand (DASH) score, range of movement, strength, morbidity and rates of reoperation. Isolated lunotriquetral injury was confirmed by arthroscopy or arthrotomy. The mean age of the patients was 30.7 years (15.4 to 53.7) and the injuries were subacute or chronic in 98.2%. Eight patients underwent lunotriquetral reconstruction using a distally-based strip of the tendon of extensor carpi ulnaris, 27 had lunotriquetral repair and 22 had lunotriquetral arthrodesis. The mean follow-up was 9.5 years (2 to 22). The probability of remaining free from complications at five years was 68.6% for reconstruction, 13.5% for repair, and less than 1% for arthrodesis. Of the lunotriquetral arthrodeses, 40.9% developed nonunion and 22.7% developed ulnocarpal impaction. The probability of not requiring further surgery at five years was 68.6% for reconstruction, 23.3% for repair and 21.8% for arthrodesis. The DASH scores for each group were not significantly different. Objective improvements in strength and movement, subjective indicators of pain relief and satisfaction were significantly higher in the lunotriquetral repair and reconstruction groups than in those undergoing arthrodesis.

OBJECTIVEReconstructive options for brachial plexus lesions continue to expand and improve. The purpose of this study was to evaluate the prevalence and quality of restored elbow extension in patients with brachial plexus injuries who underwent transfer of the spinal accessory nerve to the motor branch of the radial nerve to the long head of the triceps muscle with an intervening autologous nerve graft and to identify patient and injury factors that influence functional triceps outcome.METHODSA total of 42 patients were included in this retrospective review. All patients underwent transfer of the spinal accessory nerve to the motor branch of the radial nerve to the long head of the triceps muscle as part of their reconstruction plan after brachial plexus injury. The primary outcome was elbow extension strength according to the modified Medical Research Council muscle grading scale, and signs of triceps muscle recovery were recorded using electromyography.RESULTSWhen evaluating the entire study population (follow-up range 12–45 months, mean 24.3 months), 52.4% of patients achieved meaningful recovery. More specifically, 45.2% reached Grade 0 or 1 recovery, 19.1% obtained Grade 2, and 35.7% improved to Grade 3 or better. The presence of a vascular injury impaired functional outcome. In the subgroup with a minimum follow-up of 20 months (n = 26), meaningful recovery was obtained by 69.5%. In this subgroup, 7.7% had no recovery (Grade 0), 19.2% had recovery to Grade 1, and 23.1% had recovery to Grade 2. Grade 3 or better was reached by 50% of patients, of whom 34.5% obtained Grade 4 elbow extension.CONCLUSIONSTransfer of the spinal accessory nerve to the radial nerve branch to the long head of the triceps muscle with an interposition nerve graft is an adequate option for restoration of elbow extension, despite the relatively long time required for reinnervation. The presence of vascular injury impairs functional recovery of the triceps muscle, and the use of shorter nerve grafts is recommended when and if possible.

IntroductionVascularized bone allotransplantation may provide new options for reconstruction of segmental defects if problems of long‐term immune modulation can be solved. The current literature lacks an orthotopic large animal model, limited to bone and without the confounding effects of other tissue types, permitting a multifaceted evaluation before new methods are used clinically. The purpose of this study was to develop a large animal model for vascularized bone allotransplantation.Materials and methodsEight porcine hind limbs were dissected. Length, diameter, and location of all hindlimb vessels were measured and a single nutrient vessel supplying the tibial diaphysis identified enabling its use as a vascularized bone allotransplant. Four Yucatan minipigs were divided into two pairs with a major swine leukocyte antigen mismatch. A 3.5 cm tibial segment including its nutrient pedicle was raised simultaneously from each pig and transplanted into the matched defect of the other animal. Microarterial anastomosis of the pedicle and 3‐drug immunosuppression maintained VCA viability. Bone healing and limb function were followed for 16 weeks.ResultsA consistent tibia diaphyseal nutrient artery arose from the caudal tibial artery to enter bone a mean 2.8 mm distal to the tibial tubercle with a pedicle length of 6.6 ± 3.3 mm and diameter of 1.6 ± 0.2 mm. Using this pedicle, we reconstructed a 3.5 cm tibial defect with a vascularized bone allotransplant in four animals. Immediate weightbearing as well as progressive bone healing was demonstrated.ConclusionWe have developed a vascularized tibial bone allotranplantation large‐animal model suitable for future bone‐only allotranplantation research in mini‐pigs.