Aims. Little is known about the effect of haemorrhagic shock and resuscitation on fracture healing. This study used a rabbit model with a femoral osteotomy and fixation to examine this relationship. Materials and Methods. A total of 18 male New Zealand white rabbits underwent femoral osteotomy with intramedullary fixation with ‘shock’ (n = 9) and control (n = 9) groups. Shock was induced in the study group by removal of 35% of the total blood volume 45 minutes before resuscitation with blood and crystalloid. Fracture healing was monitored for eight weeks using serum markers of healing and radiographs. Results. Four animals were excluded due to postoperative complications. The serum concentration of osteocalcin was significantly elevated in the shock group postoperatively (p < 0.0001). There were otherwise no differences with regard to serum markers of bone healing. The callus index was consistently increased in the shock group on anteroposterior (p = 0.0069) and lateral (p = 0.0165) radiographs from three weeks postoperatively. The control group showed an earlier decrease of callus index. Radiographic scores were significantly greater in the control group (p = 0.0025). Conclusion. In a rabbit femoral osteotomy model with intramedullary fixation, haemorrhagic shock and resuscitation produced larger callus but with evidence of delayed remodelling. Cite this article: Bone Joint J 2018;100-B:1234–40

Aims. The management of a significant bony defect following excision of a diaphyseal atrophic femoral nonunion remains a challenge. We present the outcomes using a combined technique of acute femoral shortening, stabilized with a long retrograde intramedullary nail, accompanied by bifocal osteotomy compression and distraction osteogenesis with a temporary monolateral fixator. Patients and Methods. Eight men and two women underwent the ‘rail and nail’ technique between 2008 and 2016. Proximal locking of the nail and removal of the external fixator was undertaken once the length of the femur had been restored and prior to full consolidation of the regenerate. Results. The mean lengthening was 7 cm (3 to 11). The external fixator was removed at a mean of 127 days (57 to 220). The mean bone healing index was 28 days/cm and the mean external fixation index was 20 days/cm (11 to 18). There were no superficial or deep infections. Conclusion. This small retrospective study shows encouraging results for a combined technique, enabling compression of the femoral osteotomy, alignment, and controlled lengthening. Removal of the fixator and proximal locking of the nail reduces the risk of complications and stabilizes the femur with the maximum working length of the nail. Cite this article: Bone Joint J 2018;100-B:634–9

Introduction. The management of a significant bone defect following excision of a diaphyseal atrophic femoral non-union remains a challenge. Traditional bone transport techniques require prolonged use of an external fixator with associated complications. We present our clinical outcomes using a combined technique of acute femoral shortening, stabilised with a deliberately long retrograde intramedullary nail, accompanied by bifocal osteotomy compression and distraction osteogenesis to restore segment length utilising a temporary monolateral fixator. Method. 9 patients underwent the ‘rail and nail’ technique for the management of femoral non-union. Distraction osteogenesis was commenced on the 6. th. post-operative day. Proximal locking of the nail and removal of the external fixator was performed approximately one month after length had been restored. Full weight bearing and joint rehabilitation was encouraged throughout. Consolidation was defined by the appearance of 3 from 4 cortices of regenerate on radiographs. Results. 7 males and 2 females of adult age underwent treatment between 2009 and 2016. The mean lengthening was 6.6cm (3–10cm). The external fixator was removed at a mean 123 days (57–220), with an external fixation index of 20 days/cm. The regenerate healing index was 28 days/cm. There were no deep infections. Significant complications were seen in 4 patients including knee stiffness, a foot drop, delayed union of the non-union osteotomy (requiring exchange nailing and bone grafting) and revision nailing due to a prominent proximal tip. Conclusion. The combined over-sized intramedullary nail and external fixator enables compression of the femoral osteotomy, alignment of the bone and controlled lengthening. Once the length has been restored, removal of the external fixator and proximal locking of the nail reduces the risk of complications associated with the fixator and stabilises the femur with the maximum working length of the nail. This small retrospective study demonstrates encouraging results for this complex clinical scenario

There is evidence that fracture healing is delayed in severely injured patients. We recently demonstrated that a blunt chest trauma, which induced posttraumatic systemic inflammation, considerably impaired fracture healing in rats. Because the complement anaphylatoxin C5a is an important trigger of systemic inflammation, we tested the hypothesis, whether the impairment of fracture healing observed after a severe trauma resulted from systemically activated complement. 16 male Wistar rats received a thoracic trauma and a femur osteotomy stabilized by an external fixator. Immediately and 12 h after the trauma, half of the animals received a C5aR-antagonist to prevent the C5a-dependent systemic inflammation. Control rats received a nonsense peptide, which does not provoke any biological effect. The animals were killed after 35 days and the calli were analyzed by three point bending testing, μCT and histomorphometry. Statistics: Mann-Whitney U test, level of significance to p<0.05. The treatment with the C5aR-antagonist increased flexural rigidity significantly by 55%, improved bony bridging of the fracture gap and led to a slightly larger and qualitatively improved callus as evaluated by μCT and histological measurements. This study shows, that the immunomodulation by a C5aR-antagonist significantly reduced the deleterious effects of a thoracic trauma on fracture healing. C5a could possibly represent a target to prevent delayed bone healing in patients with severe trauma

Hypothesis. The proximal geometry and design of trochanteric nails affects initial construct stiffness, fatigue survival, and preservation of biomechanical stability over time. Materials & Methods. Eight pairs of human cadaveric femora were implanted with two different short intramedullary nails with (Intertan, (S&N)) and without (Gamma 3, (Stryker)) interlocking lag screws. Femoral osteotomies were performed to generate a pertrochanteric multifragmentary unstable fracture (OTA 31-A 2.2). The bones were tested in a cyclic testing protocol with increasing loads of 100 N every 20.000 cycles (start point 50/500 N) simulating one leg stance. The position of the femur was 10° adduction and 10° extension. Stiffness, failure load, and cycles to failure were measured. Results. Initially, stiffness of the interlocking lag screw nail was 40 % higher (p < 0,05) than for the non-interlocking nail. During the test, the difference in stiffness gradually decreased. Load to failure (9 %, p < 0,05) and cycles to failure (13 %, p < 0,05) were also higher for the interlocking nail construct. Discussion & Conclusion. The interlocking screw design of intramedullary nail constructs improves the mechanical performance in unstable trochanteric fractures. This may result in improved clinical performance

In polytrauma patients invasive surgeries can potentiate the posttraumatic systemic inflammation thus increasing the risk of multi organ dysfunction. Therefore, fractures are initially treated by external fixators, which later are replaced by intramedullary nails. We showed that a severe trauma impaired the healing of fractures stabilized by external fixation. Here we studied, whether the conversion to an intramedullary nail increases posttraumatic inflammation and leads to further impairment of healing. 44 rats received a femur osteotomy stabilized by an external fixator (FixEx). Half of the rats underwent a thoracic trauma (TXT) at the same time. After 4 days the fixator was replaced by an intramedullary nail (IMN) in half of the rats of each group. The rats were killed after 40 and 47 days. C5a serum levels were measured 0, 6, 24, and 72h after the 1st as well as the 2nd surgery. The calli were evaluated by three-point-bending test, μCT and histomorphometry. The TXT significantly increased serum C5a levels after the 2nd surgical intervention. After 40 days the switch from FixEx to IMN significantly decreased bending stiffness in rats with and without TXT. After 47 days flexural rigidity in rats subjected to conversion was significantly decreased compared to rats treated only with a FixEx, particularly in combination with TXT. This study showed that after a severe trauma the conversion of the fixation could provoke a second hit and contribute to delayed fracture healing

There is evidence that fracture healing is impaired in patients with chronic immune disorders the reasons remaining unclear so far. To further elucidate the role of the immune system in bone healing, this study investigated the hypothesis that fracture healing would be considerably disturbed in a mouse model with severe defects of the innate as well as adaptive immune system. Immune deficient Nod-scidIL2Rγ. null. and immune competent BALBcByJ mice were used (12 weeks, male, each n=24). The mice received a femur osteotomy stabilized by an external fixator and were sacrificed at d 21, 28, and 35. The calli were evaluated by three-point-bending testing, μCT and histomorphometry. The flexural rigidity of the callus did not significantly differ between both genotypes after 21 and 28 days but was significantly lower in Nod-scidIL2Rγ. null. mice after 35 days (31%). The maximum moment of inertia was significantly increased after 21 days (by 34%), and the callus cross section area after 21, 28 and 35 days in Nod-scidIL2Rγ. null. mice. BV/TV of the callus of Nod-scidIL2Rγ. null. mice was significantly decreased after 28 and 35 days (by 32% and 41%). The histological evaluation showed a significantly enhanced amount of cartilage in the fracture gap of Nod-scidIL2Rγ. null. mice. These data indicate an only moderate delay in fracture healing in Nod-scidIL2Rγ. null. mice suffering on severe defects in innate and adaptive immune response

Introduction. Total Hip Arthroplasty (THA) in patients after proximal femoral osteotomy remains a major challenge. Inferior survival for both cementless and cemented THA has been reported in this subgroup of patients. Methods. We retrospectively evaluated the clinical and radiographic results of a consecutive series of 48 THAs (45 Patients) who had undergone conversion THA for failed intertrochanteric osteotomy after a mean of 12 years (2–33 years) using a cementless, grit-blasted, double-tapered femoral stem. Mean follow-up was 20 years (range, 15–25 years), mean age at surgery was 47 years (range, 13–55 years). Clinical results were evaluated using the Harris Hip Score. Kaplan-Meier survivorship analysis was performed to determine long-term outcomes for different end points. Results. At follow-up, 10 patients (11 hips) had died, and 1 patient (1 hip) was lost to follow-up. Five patients (5 hips) underwent femoral revision, 2 for infection and 3 for aseptic loosening of the stem. Overall stem survival was 91% at 20 years (95%-CI: 78%–97%); survival with femoral revision for aseptic loosening as end point was 93% (95%-CI: 80%–98%). Discussion and Conclusion. The long-term results with this type of cementless femoral component in young patients with failed intertrochanteric osteotomy are encouraging and compare well to those achieved in patients with regular femoral anatomy

Background. Several risk factors for the development of osteonecrosis following treatment of developmental dislocated hip have been reported. The need for further research with a large-enough sample size including statistical adjustment of confounders was demanded. The purpose of the present study was to find reliable predictors of osteonecrosis in patients managed for developmental dislocation of the hip. Methods. A retrospective cohort study of children, who have been hospitalized at our department between January 1998 and February 2007 with a developmental dislocation of the hip, was completed. Sixty-four patients satisfied the criteria for inclusion. Three groups according to age and treatment were identified. Group A and B included patients treated with closed or open reductions aged less than twelve months. Patients of group C were past walking age at the time of reduction and were treated by open reduction combined with concomitant pelvic and femoral osteotomies. The average duration of follow-up for all patients was 6.8 years. Logistic regression analysis was conducted to identify predictors for the development of osteonecrosis. Results. The overall rate of osteonecrosis in group A and B was 27.4% compared to 88.2% in patients of group C. After pooling of all data, no protective effect of the ossific nucleus of the femoral head on the development of osteonecrosis was found (p = 0.14). Additionally, an increase of surgical procedures in children of group C could not be demonstrated (p = 0.17). By using logistic regression analysis the type of reduction and secondary reconstructive procedure due to residual acetabular dysplasia could be identified as predictors for the development of osteonecrosis. Conclusions. Open reduction combined with concomitant osteotomies and secondary reconstructive interventions due to residual acetabular dysplasia increase the risk for osteonecrosis in the treatment of the developmental dislocated hip. Therefore, we advocate early reduction of the dislocated hip in the first year of life to avoid the need for concomitant osteotomies combined with open reduction. Level of Evidence. Prognostic study, level II-1 (retrospective study)

Aim. to compare the medium term clinical and functional results of total hip arthroplasty after intertrochanteric osteotomy and primary total hip replacement. Material and methods. We compared 2 groups of patients: Group I-93 patients with total hip arthroplasty after intertrochanteric osteotomy and Group II-93 patients with primary total hip arthroplasty. The patients in the control group (Group II) were randomly chosen from the cases operated by the same surgical team using the same kind of implant like those in Group I. The osteotomies were of different types: medial displacement (27), varisation(19), valgisation (18), flexion(25), rotational (4). The demographic parameters were similar in the 2 groups. Technical intraoperative challenges were noted. The Harris Score was determined at 12 months and 3 years after surgery. Clinical and radiological check-ups were performed each year. The duration of each surgical procedure was recorded. Complications were noted during the entire follow-up. The mean follow-up was 77 months. Results. The average time interval between osteotomy and total hip replacement was 76 months. The average Harris Score (HHS) at 1 year after surgery was 88 in Group I and 93 in Group II. At 3 years, the average values of HHS were 85 in the first group and 92 in the second. After an average follow-up of 6 years, 6 patients in group I (6,45%) required revision arthroplasty, while in the second group this procedure was not necessary. The indication of revision was loosening of the femoral component in 4 cases and of both components in 2 cases. The duration of a total hip arthroplasty after an ostheotomy was almost two times longer than a primary total hip replacement. In most cases, the surgical procedure implicated removal of a blade plate or others fixation devices, reaming of the femur, osteotomies of the greater trochanter, reverse osteotomies of the intertrochanteric region and the use of special design (thin or curved) femoral stems. In group I, intraoperative complications included fractures of the femoral diaphysis, fractures of the greater trochanter, false passage for the femoral component and malposition of the femoral stem. Postoperative complications consist in dislocations, early loosening, heterotopical ossifications, wound sepsis, etc. Conclusions. Total hip arthroplasties after intertrochanteric osteotomies have clinical results a little bit inferior of those of primary total hip replacements, but the difference is not significative. The survival rate of prosthesis implanted after intertrochanteric osteotomies at 6 years is significantly inferior. Both the intraoperative and postoperative complications rates are far superior of those of the primary arthroplasties

Background. Habitual hip subluxation and dislocation is a potentially disabling feature of Trisomy 21. We describe long-term outcomes following precise use of the femoral varus derotation osteotomy to achieve and maintain hip stability and community ambulation. Methods. All individuals with Trisomy 21, who had hip surgery at Toronto's Hospital for Sick Children between 1998 and 2008, were searched using the hospital databases. 16 hips in 9 children aged less than 10 years, were identified. All had a femoral varus derotation osteotomy (VDRO) with a target femoral neck shaft angle (NSA) of 105° and less than 20° external rotation. All were performed by the senior author JHW. The clinical notes and radiographs were reviewed from presentation to final follow up. Continuous variables were assessed for normality with the d'Agostino Pearson test. Normally distributed variables are presented as means with 95% confidence intervals. Pre and postoperative means were compared using the student's t-test for paired samples. Results. Mean age at first known hip dislocation was 4.56 years (3.98, 5.15), mean age at surgery 6.07 years (5.15, 7.0) and mean follow-up 5.4 years (3.75, 7.06). Mean femoral neck shaft angle (NSA) fell from 166.7° (162.2°, 171.1°) to 106.0° (103.1°, 110.2°). In 2 hips, significant intraoperative instability persisted and periacetabular osteotomies with capsulorraphies were required. All patients developed an asymptomatic waddling gait postoperatively. 14 hips developed peritrochanteric varus deformities, mean 20.7° (15.96°, 25.4°)2 (12.5%) sustained periprosthetic fractures 4 and 8 years postoperatively. 1 hip (6.2%) developed painful arthritis. None re-dislocated at latest follow up. Conclusion. Prevention of long term disabling pain from habitually dislocating or recurrently subluxed hips, in patients with Trisomy 21, requires surgical intervention to increase hip containment. We believe surgical management of habitually subluxed or dislocated Trisomy 21 hips allows for a predictable result. We recommend a varus producing proximal femoral osteotomy to correct the NSA to 105° with less than 20° of external rotation. This technique was successful at restoring and maintaining hip stability in 16 hips with a mean follow-up of 5.4 years, whilst maintaining the patient's ability to remain community ambulators. It should be performed before aged 8 or signs of a widened or V-shape teardrop develops. In our experience this has been effective in maintaining hip stability. However, little is known about the natural history of habitual hip dislocation in these children. Patients with Trisomy 21 are living longer with hips that are at continuous risk. Thought should be given to the potential benefits of periodic screening of this treatable hip condition

Aims

Hospital case volume is shown to be associated with postoperative outcomes in various types of surgery. However, conflicting results of volume-outcome relationship have been reported in hip fracture surgery. This retrospective cohort study aimed to evaluate the association between hospital case volume and postoperative outcomes in patients who had hip fracture surgery. We hypothesized that higher case volume would be associated with lower risk of in-hospital and one-year mortality after hip fracture surgery.

Fracture repair occurs by two broad mechanisms: direct healing, and indirect healing with callus formation. The effects of bisphosphonates on fracture repair have been assessed only in models of indirect fracture healing.

A rodent model of rigid compression plate fixation of a standardised tibial osteotomy was used. Ten skeletally mature Sprague–Dawley rats received daily subcutaneous injections of 1 µg/kg ibandronate (IBAN) and ten control rats received saline (control). Three weeks later a tibial osteotomy was rigidly fixed with compression plating. Six weeks later the animals were killed. Fracture repair was assessed with mechanical testing, radiographs and histology.

The mean stress at failure in a four-point bending test was significantly lower in the IBAN group compared with controls (8.69 Nmm^-2 (sd 7.63) vs 24.65 Nmm^-2 (sd 6.15); p = 0.017). On contact radiographs of the extricated tibiae the mean bone density assessment at the osteotomy site was lower in the IBAN group than in controls (3.7 mmAl (sd 0.75) vs 4.6 mmAl (sd 0.57); p = 0.01). In addition, histological analysis revealed progression to fracture union in the controls but impaired fracture healing in the IBAN group, with predominantly cartilage-like and undifferentiated mesenchymal tissue (p = 0.007).

Bisphosphonate treatment in a therapeutic dose, as used for risk reduction in fragility fractures, had an inhibitory effect on direct fracture healing. We propose that bisphosphonate therapy not be commenced until after the fracture has united if the fracture has been rigidly fixed and is undergoing direct osteonal healing.

Cite this article: Bone Joint J 2013;95-B:1263–8.

Objectives

One commonly used rat fracture model for bone and mineral research is a closed mid-shaft femur fracture as described by Bonnarens in 1984. Initially, this model was believed to create very reproducible fractures. However, there have been frequent reports of comminution and varying rates of complication. Given the importance of precise anticipation of those characteristics in laboratory research, we aimed to precisely estimate the rate of comminution, its importance and its effect on the amount of soft callus created. Furthermore, we aimed to precisely report the rate of complications such as death and infection.

Objectives

Small animal models of fracture repair primarily investigate indirect fracture healing via external callus formation. We present the first described rat model of direct fracture healing.