Ectopic bone formation after medial femoral condyle graft to scaphoid nonunion

Symptomatic Heterotopic Bone Formation after 1,2 ICSRA in Scaphoid Nonunions

Background  We observed several cases of heterotopic bone formation after a 1,2 intercompartmental supraretinacular artery (1,2 ICSRA) distal radius vascularized bone graft (VBG) for the treatment of scaphoid nonunion. This adverse event seems underreported. Knowledge about factors associated with the formation of heterotopic bone after VBGs might help reduce this adverse event. Purpose  What factors are associated with resected heterotopic bone formation after 1,2 ICSRA distal radius graft for the treatment of scaphoid nonunion? Patients and Methods  We retrospectively reviewed all patients with a scaphoid nonunion treated with a 1,2 ICSRA distal radius graft between 2008 and 2019 in an urban level 1 trauma center in the Netherlands. We included 42 scaphoid nonunions in 41 people treated with the 1,2 ICSRA graft. We assessed potential correlation with patient, fracture, and treatment demographics. Results  Heterotopic bone developed in 23 VBGs (55% [23/42]), of which 5 (12% [5/42]) were resected. Heterotopic bone was located radially (at the pedicle side) in all participants. Except a longer follow-up time ( p  = 0.028), we found no variables associated with the development of heterotopic bone formation. Conclusion  The location of the heterotopic bone at the pedicle site in all cases suggests a potential association with the periosteal strip. Surgeons might consider not to oversize the periosteal strip as a potential method to prevent heterotopic ossification after VBG. Level of Evidence  Level II, prognostic study.

[Scaphoid non-union: Experience from more than 280 reconstructions using a medial femur condyle bone graft]

BACKGROUND

Since 2008 we have been using many free vascularized medial femoral condyle grafts for reconstruction of difficult scaphoid non-unions. This article aims to report our results and experiences.

PATIENTS AND METHODS

Until the end of 2019 a total of 287 patients had a microvascular scaphoid reconstruction, 158 with use of a corticocancellous, and 129 using an osseocartilaginous graft. Complete analysis of all of these patients was impossible. This manuscript is based on a retrospective analysis of 28 out of 42 patients with corticocancellous grafts operated on between 2008 and 2010 with a mean follow-up time of 6.1 years as well as another 44 out of 76 patients with an osseocartilaginous graft operated on between 2011 and 2016 with a mean follow-up time of 44 months. Follow-up included clinical parameters, conventional x-rays, a DASH-Score and a modified Mayo wrist score. Additionally, the authors report their personal experiences - necessarily without quantification. In view of this incomplete data-pool statistical analysis was not reasonable.

RESULTS

In the group with corticocancellous reconstructions bony healing was achieved in 69 %, salvage operations were required in 9,5 %. The 28 patients had a mean DASH-Score of 11, a mean modified Mayo wrist score of 83 points, a mean ROM of 86° and a mean grip strength of 89 % of the contralateral side. In the group with osseocartilaginous reconstructions complete bony healing was seen in 80 %, partial healing in 5 %, and salvage procedures were required in 11 %. The remaining 39 patients had a mean DASH-Score of 15, a mean modified Mayo wrist score of 80 points, a mean ROM of 90° and a grip strength of 81 % of the contralateral hand. A specific complication was an ossification of the pedicle, but the main problem was a satisfying reconstruction of the shape of the scaphoid and reestablishment of carpal stability in far advanced cases. We could not identify factors reliable for the persisting non-unions.

CONCLUSIONS

These operations combine great chances for healing with considerable risks for serious complications. So future patients have to be fully informed, so that their decision for such a procedure is based on realistic expectations.

[Nitinol memory alloy two foot fixator with autologous cancellous bone grafting for old scaphoid fracture and nonunion]

Objective

To summarize the effectiveness of nitinol memory alloy two foot fixator with autologous cancellous bone grafting in treating old scaphoid fracture and nonunion.

Methods

Between January 2013 and January 2017, 11 patients of old scaphoid fracture and nonunion were treated with nitinol memory alloy two foot fixator and autologous cancellous bone grafting. All patients were male with an average age of 26.1 years (range, 18-42 years). The fractures were caused by sport in 3 cases, falling in 7 cases, and a crashing object in 1 case. The interval between injury and operation was 6-18 months (mean, 8.9 months). Postoperative outcome measures included operation time, fracture healing time, grip strength, range of motion (ROM) of flexion, extension, ulnar deviation, and radial deviation, Mayo score, visual analogue scale (VAS) score, and the Disabilities of the Arm, Shoulder, and Hand (DASH) score.

Results

The operation time was 35-63 minutes (mean, 48 minutes). All incisions had primary healing with no infection and loosening or breakage of internal fixator. All patients were followed up 12-30 months (mean, 20.7 months). X-ray films showed that fracture healing was achieved in all patients with an average time of 15 weeks (range, 12-25 weeks). All internal fixators were removed after 10-12 months of operation (mean, 11.2 months). At last follow-up, the grip strength, ROMs of flexion, ulnar deviation, and radial deviation were superior to those before operation ( P<0.05), no significant difference was found in ROM of extension between pre- and post-operation ( t=0.229, P=0.824). There were significant differences in above indexes between affected and normal sides ( P<0.05). At last follow-up, the Mayo, VAS, DASH scores were also significantly superior to those before operation ( P<0.05).

Conclusion

For the old scaphoid fracture and nonunion, Ni-Ti arched shape-memory alloy fixator and autologous cancellous bone grafting can obtain good effectiveness, which is an effective treatment.

Combined Pedicled Vascularized and Wedge Nonvascularized Bone Graft for Treating Scaphoid Waist Nonunion With Humpback Deformity

Pedicled vascularized bone graft (VBG) is a useful method in treating the scaphoid fracture nonunion, especially when the avascular necrosis exists. Humpback deformity is an important issue that we have to correct it during the treatment. We describe a method by using combined wedge non-VBG to correct the nonunion deformity when treating scaphoid nonunion with pedicled VBG. The wedge bone graft was harvested just proximal to the 2,3 intercompartmental supraretinacular artery VBG and was used as an inlay at the volar site to correct the humpback deformity, whereas the VBG was set at the dorsal site for bone bridging and blood supply. We also present our results of 10 patients with scaphoid fracture nonunion and humpback deformity treated with this method. Bone healing was achieved and the lateral intrascaphoid angles could be improved in all the 10 patients. Functional outcomes, including the Visual Analog Pain Scale for pain during activity, grip strength, the shortened Disabilities of the Arm, Shoulder, and Hand questionnaire (QuickDASH), and the modified Mayo Wrist Scores, were significantly improved.

[Scaphoid pseudarthrosis : Complex reconstruction using vascularized bone grafts]

The most important goals of scaphoid reconstruction in pseudarthrosis are correction of the humpback deformity, the realignment of the proximal carpal row and the bony union of the scaphoid. Therefore, in most cases bone grafting is required. To increase the healing rate and to improve vascularization, several kinds of vascularized bone grafts have been developed. Pedicled grafts are preferably harvested from the dorsal or palmar side of the distal radius with fusion rates between 27% and 100%. Free microvascular grafts can be obtained from the iliac crest and the medial or lateral femoral condyle with fusion rates between 60% and 100%. For their application microsurgical equipment and skills are required. Up to now osteochondral grafts from the femoral condyle offer the only chance for joint surface replacement by transferring part of the surface of the femoropatellar joint. The use of vascularized grafts is still a matter of controversy, since their superiority is still unproven compared to nonvascularized grafts, which also achieved 100% fusion rates in several series. They are indicated in secondary procedures after failed reconstruction and nonunion with small avascular proximal pole fragments. Since no evidence-based guidelines exist, this article provides an experience-based treatment algorithm for scaphoid nonunion with special consideration to vascularized bone grafts.

The Vascularity and Osteogenesis of a Vascularized Flap for the Treatment of Scaphoid Nonunion: The Pedicle Volar Distal Radial Periosteal Flap

Background: Vascularized periosteal flaps from the distal radius have been previously proposed. The purpose of this study was to investigate the vascularity and osteogenic potential of a vascularized volar distal radial periosteal flap for the treatment of scaphoid nonunion. Methods: In 5 fresh frozen cadavers, a rectangular periosteal flap was elevated from the distal radius with the pedicle just proximal to the watershed line. Latex dye was injected into the radial artery proximally and the vascularity of the flap characterized by microscopic evaluation. Patients with scaphoid nonunion were then treated with open reduction, internal fixation, and distal radius cancellous bone graft. Two groups of patients with midwaist nonunion scaphoid were then evaluated. The first group received the vascularized periosteal flap and the second group received a nonvascularized periosteal flap. A third group of proximal pole nonunions also received the vascularized flap. Results: Cadaveric dissections revealed that all of the injected flaps demonstrated vascularity to the distal edge of the flap. Vascularized flaps formed visible bone on imaging in 55% of cases. None of the nonvascularized flaps formed visible bone. In group 1, 12/12 midwaist nonunions united. In group 2, union was achieved in 6/6 of patients who completed the follow-up. In group 3, 6/7 proximal pole fractures united. Conclusions: Previously proposed vascularized periosteal flaps from the distal radius appear to possess notable osteogenic potential that may be of interest to surgeons treating scaphoid nonunion.

Combined treatment with extracorporeal shock‑wave therapy and bone marrow mesenchymal stem cell transplantation improves bone repair in a rabbit model of bone nonunion

The aim of the present study was to analyze whether extracorporeal shock‑wave therapy (ESWT) combined with bone marrow mesenchymal stem cell (BMMSC) transplantation improves bone repair in a rabbit bone nonunion model. ESWT combined with BMMSC effectively enhanced mechanical strength, fracture stiffness and histological scores, and increased alkaline phosphatase activity, and osteopontin, runt related transcription factor 2 and collagen type I α1 chain protein expression levels in a rabbit bone nonunion model. In addition, ESWT combined with BMMSC effectively enhanced insulin‑like growth factor 1 and vascular endothelial growth factor contents, promoted transforming growth factor‑β (TGF‑β) contents, and induced the growth factors, bone morphogenetic protein (BMP)‑2, BMP‑4 and purinergic receptor P2X7 (P2X7) protein expression in the rabbit bone nonunion model. Thus, the present study demonstrated that ESWT combined with BMMSC transplantation improves bone repair in a rabbit bone nonunion model via the BMPs and P2X7 signaling pathways.