Aims. There is ambiguity surrounding the degree of scaphoid union required to safely allow mobilization following scaphoid waist fracture. Premature mobilization could lead to refracture, but late mobilization may cause stiffness and delay return to normal function. This study aims to explore the risk of refracture at different stages of scaphoid waist fracture union in three common fracture patterns, using a novel finite element method. Methods. The most common anatomical variant of the scaphoid was modelled from a CT scan of a healthy hand and wrist using 3D Slicer freeware. This model was uploaded into COMSOL Multiphysics software to enable the application of physiological enhancements. Three common waist fracture patterns were produced following the Russe classification. Each fracture had differing stages of healing, ranging from 10% to 90% partial union, with increments of 10% union assessed. A physiological force of 100 N acting on the distal pole was applied, with the risk of refracture assessed using the Von Mises stress. Results. Overall, 90% to 30% fracture unions demonstrated a small, gradual increase in the Von Mises stress of all fracture patterns (16.0 MPa to 240.5 MPa). All fracture patterns showed a greater increase in Von Mises stress from 30% to 10% partial union (680.8 MPa to 6,288.6 MPa). Conclusion. Previous studies have suggested 25%, 50%, and 75% partial union as sufficient for resuming hand and wrist mobilization. This study shows that 30% union is sufficient to return to normal hand and wrist function in all three fracture patterns. Both 50% and 75% union are unnecessary and increase the risk of post-fracture stiffness. This study has also demonstrated the feasibility of finite element analysis (FEA) in scaphoid waist fracture research. FEA is a sustainable method which does not require the use of finite scaphoid cadavers, hence increasing accessibility into future scaphoid waist fracture-related research. Cite this article: Bone Jt Open 2023;4(8):612–620

Between the years 1999 and 2001, approximately 3000 expandable intramedullary nails were used worldwide in various surgical procedures. From this number, 250 of these nails were used for traumatic fractures and are the focus of the study presented here. The subjects consisted of 160 males and 90 females with a mean age of 41 years. Initial radiographs were obtained for all subjects. Additional X-rays and follow-up data were reported for only 75 patients (30%) with follow-up time averaging 18 weeks. Most of the fractures occurred in the midshaft (64%), followed by distal thirds (22%), and then proximal (14%). The group was then divided according to fracture location: humerus, tibial and femur. The nail was used in 92 humerus fractures. Follow-up data was available for 35 patients with a follow-up time averaging 16 weeks. The nail was inserted retrograde in 61% of the patients and antigrade in 39% of the patients. Partial reaming was done in 42% of the cases. Mean operating time was 52 minutes and fluoroscopy time was 3.8 minutes. Anatomical reduction was achieved in 96% of the cases and in 4% of the cases, acceptable reduction was achieved with a varus < 10°. Surgical outcomes included 28 complete bone union, and 7 partial union. Eight nails were removed after complete union was achieved. In addition, the inflatable nail was used for treatment of 114 tibial fractures. In 39% of the cases a partial reaming was done. Average operating time was 39 minutes and fluoroscopy time was 3.4 minutes. All the fractures were reduced anatomically. In 25 patients with mean follow-up of 18 weeks, 14 united completely and 11 united partially. Nine nails were removed after completion of the union. Data on 44 patients with femoral fractures treated by the inflatable nail were also reported. Only 15 patients were available for follow-up with an average of 21 weeks follow-up time. Nail insertion by the antegrade approach was used in 89% of the patients and the retrograde approach was used in 11% of the patients. Partial reaming was done in 44% of the cases. Mean operating time was 60 minutes and fluoroscopy time 7.5 minutes. Anatomical reduction was achieved in all with the exception of two patients with mild valgus deformity (< 10°). By the end of the study period, 8 had complete union, 7 had partial union. In summary, the nail was found to be very effective and safe. The surgeons who performed the surgery reported that surgical and fluoroscopy time were both reduced by half. Reaming was not mandatory and this contributed to the shortened operating time. No complications were encountered during extraction of all the nails after completion of union, even in those patients in whom the nail developed an hour glass configuration according to the size of the medullary canal. It is still too early to conclude if this nail will produce better or equal results to the conventional interlocking nails. Nevertheless, the lack of reaming, locking, and the low contact area of the nail with the medullary canal, may explain the rapid healing observed in some cases

We present a series of 23 total ankle replacements revised for balloon osteolysis and aseptic loosening with a hind-foot fusion nail without the use of bone graft. This is the largest series of total ankle replacements revised to a hindfoot fusion with a nail presented in the literature. Initial assessment involved investigations to rule out infection and a CT scan of the ankle to assess the size of cysts. Patients underwent surgery in a single stage procedure. The surgery involved excision of the fibula and preparation of the sub-talar joint through a lateral incision; removal of the implant and preparation of the talar and tibial surface with flat cuts through an anterior incision and safe excision of the medial malleolus aided by a medial incision. The prepared surfaces were then compressed and fixed using a Biomet Phoenix Nail. Patients were then followed up to assess for clinical and radiographic union. This study involved 18 male and 4 female patients with an average age of 67. All patients had AES ankle replacements (Biomet) in-situ, undergoing revision surgery for aseptic loosening with balloon osteolysis. At a mean follow up of 13.9 months, 96% (22/23) of ankles achieved osseous union across the tibio-talar joint with 1 patient achieving a partial union. 91% (21/23) of patients achieved union across the subtalar joint with 2 patients identified as having a non-union. 1 patient with a subtalar non-union suffered a broken nail and required revision surgery. The only other identifiable complication was a single patient sustained a stress fracture at the proximal tip of the nail, which was treated conservatively. We believe this method is a reliable and reproducible method of achieving osseous union following a failed total ankle replacement without using graft. Although patients may have a leg length discrepancy, none have requested leg lengthening

Introduction. Nonunion is a common and costly fracture outcome. Intricate reciprocity between angiogenesis and osteogenesis means vascular cell-based therapy offers a novel approach to stimulating bone regeneration. Hypothesis. The current study compared early and late outgrowth endothelial progenitor cell subtypes (EPCs vs OECs) for fracture healing potential in vitro and in vivo. Methods. Primary cell cultures were isolated and characterized by endothelial assays, immunosorbent assays, and multi-color flow cytometry. Co-cultures of EPC subtypes with/without primary osteoblasts (pObs) were analyzed for tube length and connectivity. In vivo, EPCs or OECs (1×10. 6. ) seeded on a gelfoam scaffold were implanted in a rat model of nonunion. Radiography was used to monitor callus formation. Results. OECs expressed more BMP-2 and less VEGF than EPCs (p<0.05). Analysis of surface markers showed decreased CD34+/CD133+/Flk-1+, CD133+ and CD45+ populations in OECs while CD34+/CD31+/Flk-1+ cells increased. pObs significantly inhibited the strong tubulogenesis of OECs while enhancing connectivity and sprout length of EPCs. In vivo, 0/6 scaffold-control and 1/5 OEC rats achieved union at 10 weeks. In comparison, all EPC rats achieved full or partial union. Discussion and Conclusion. Despite favorable tubulogenic and osteoconductive profiles of OECs, EPCs display enhanced fracture healing in vivo. Differences in CXCR4 expression and cell-mediated effects may contribute to this result

Introduction: Tutobone is a solvent-preserved cancellous bovine bone substitute. There is little published about its use in humans. We have been using it as a wedge graft to correct deformity in hindfoot fusion surgery. Aim: To review the outcome following the use of Tutobone in hindfoot fusion and compare it with a control group without Tutobone. Method: We performed a retrospective review of all hindfoot fusion performed by the senior author (AG) from 1 Sep 2004 to 31 Jan 2008. We excluded all revision procedures for non-union or malunion. A CT or MRI scan was performed to assess union and graft incorporation in the Tutobone patients at more than six months postoperatively. In the control group fusion was assessed with plain radiographs. The difference in proportion of fusion with complete fusion by six months post-operatively was assessed with a Fisher’s exact test. Results: There were eleven patients in the Tutobone group (1 ankle, 7 subtalar and 3 triple fusions) and 35 in the control group (15 ankle, 11 subtalar, 3 pantalar and 6 triple fusions). All Tutobone patients had partial union on CT/MRI scans. The Tutobone graft had not incorporated at a mean time interval of 14 months post surgery. 30 out of 35 control patients had fused by six months and 33 out of 35 controls were fused by 12 months. The rate of complete fusion between the two groups at six months was statistically significant (p< 0.0001). Two Tutobone patients developed an inflammatory reaction at more than six months post fusion. This reaction is not infective and appears to be a reaction to the Tutobone. Conclusion: Tutobone should not be used in hindfoot fusion surgery

Introduction: Non-union following hindfoot arthrodesis remains a significant risk in foot and ankle surgery. In the reported series of revision hindfoot arthrodeses non-union rates range from 9 to 25% with approximately half these patients going on to a transtibial amputation. Bone morphogenic proteins (BMP) are a group of naturally occurring proteins with strong osteoinductive properties, which have shown promise in the treatment of fracture non-unions and primary hindfoot arthrodesis surgery. This article reports our experiences with rhBMP-7 as an adjunct to revision arthrodesis surgery in this high-risk subset of patients. Methods: Eight patients with at least one previous non-union and two or more risk factors for non-union and one patient on steroids with a failed total ankle replacement were prospectively recruited to the study. A revision arthrodesis procedure with internal fixation was performed according to the senior author’s revision protocol with the addition of 3.5mg rhBMP-7 combined with 40mls of bone marrow aspirate. Bone graft was used only if there was structural bone loss. Outcome was assessed clinically and radiologically. Results: Follow-up ranges from 3 to 22 months (average 13 months). Clinically 8 of the 9 patients had a pain free, stable arthrodesis. Seven patients were satisfied with their functional improvement and pain relief. Radiologically two patients have united, six patients have partial unions with ongoing progression towards union and one patient has a painless non-union. There was one wound infection and one malunion. No complications related to rhBMP-7 were experienced. Conclusion: Revision arthrodesis with adjuvant rhBMP-7 has led to limb salvage in this group of high-risk patients. However, rhBMP-7 is not a panacea for achieving union and does not replace meticulous surgical planning and technique. Achieving bony union in this subset of patients remains a high risk and protracted process. No concerns about the short-term safety of rhBMP-7 were raised

The management of upper limb nonunions can be challenging and often with unpredictable outcomes. In the study we present the results of treatment of upper limb nonunions treated in our institution with BMP-7 biological enhancement. Between 2004 and 2011 all consecutive patients who met the inclusion criteria were followed up prospectively. Union was assessed with regular radiological assessment. At the final follow up clinical assessment included the disabilities of the Arm, Shoulder and Hand (DASH) score, range of movement and patient satisfaction. The mean follow up was 12 months (12–36). In total 42 patients met the inclusion criteria with a mean age of 47. Anatomical distribution of the nonunion sites included 19 cases of mid/proximal radius/ulna, 14 humerus, 6 distal radius and 3 clavicles. 5 patients had septic nonunion, 35 had atrophic nonunion, 11 had previous open fractures, and 10 had bone loss (range 1–3 cm). The mean number of operations performed and the mean time from injury to BMP application was 1.5 and 26 months, respectively. 40 patients had both clinical and radiological union whereas 2 had partial radiological union but a pain free range of motion. BMP was applied in isolation in 1 case and 41 cases the application was combined with autologous bone grafting. The range of movement of the affected limb, DASH score and patient satisfaction were optimum at the final follow up. This study supports the use of BMP-7 as a bone stimulating adjunct for the treatment of complex and challenging upper limb nonunions