Diaphyseal Bone Loss Research Articles

Improvements in Pediatric Bone Loss Reconstruction With the Induced Membrane Technique.

The induced membrane technique is now widely used for pediatric diaphyseal bone loss due to various etiologies. Although consolidation rates remain satisfactory, complications, and healing delays may occur requiring additional procedures. We studied a series of induced membrane bone reconstructions in which the second stage included an embedded endomembranous non vascularized fibular shaft, in addition to iliac bone grafts. The purpose of this study was to analyze the results in terms of bone consolidation and complications. This is a retrospective comparative and multicentric study of 32 children with large bone loss treated with the induced membrane reconstruction technique. Patients were divided into 2 groups according to the graft used during the second stage. The first group (G1) of 16 patients had a nonvascularized fibula embedded inside the membrane in addition with the corticocancellous grafts from the iliac crest. The second group (G2) of 16 patients underwent reconstruction using the original technique, with iliac crest graft only. The 2 groups were similar in terms of etiologies of bone loss and follow-up (mean: 44mo for G1 and 49mo for G2). Mean bone losses were 15.4cm (range: 2 to 25; SD: 5.6) for G1 and 10.6cm (range: 3 to 19; SD: 5.2) for G2. In the first group, all patients healed primarily, with a mean time of 5.9 months (range: 4 to 8; SD: 1.6). In the second group, 2 of 16 patients did not healed; for the others 14, healing mean time was 6.9 months (range: 3 to 12; SD: 2.7). The short-term and long-term complications rates were 38% to 19% for G1 and 50% to 31% for G2, respectively. Regarding the donor site, the fibulas reconstructed spontaneously with a mean time of 4.8 months (range: 3 to 6; SD: 1.2). The integration of a nonvascularized fibula during the second stage of the induced membrane technique appears to improve the consolidation rate in the pediatric population. Level III-Retrospective comparative study.

Masquelet Technique: Visualization of Cement Spacer Utilizing Methylene Blue

Masquelet Technique: Visualization of Cement Spacer Utilizing Methylene Blue

Induced Membrane Technique is Effective for the Management of Acute Traumatic Bone Loss in Both Diaphyseal and Metaphyseal Lower Extremity Fractures.

To compare outcomes of Masquelet's induced membrane technique (IMT) in metaphyseal and diaphyseal fractures with acute bone loss. Retrospective cohort study Setting: Four Level 1 Academic Trauma CentersPatients/Participants: Patients acutely treated with IMT for traumatic lower extremity bone loss at four Level 1 trauma centers between 2010-2020. Operative treatment with placement of cement spacer within three weeks of initial injury followed by staged removal and bone grafting to the defect. Fracture union, infection, revision grafting, time to union, and amputation. 120 fractures met inclusion criteria, including 43 diaphyseal fractures (DIM) and 77 metaphyseal fractures (MIM). Demographic characteristics were not significantly different, except for age (DIM 34 years vs MIM 43 years, p< 0.001). Union after treatment with IMT was 89.2% overall. After controlling for age, this was not significantly different between DIM (41/43, 95.3%) and MIM (66/77, 85.7%) (p =0.13), nor was the rate of infection between groups. There was no difference in any secondary outcomes. The overall union rate in the current series of acute lower extremity fractures treated with induced membrane technique was 89%. There was no difference in successful union between patients with diaphyseal bone loss or metaphyseal bone loss treated with IMT. Similarly, there was no difference in patients with tibial or femoral bone loss treated with induced membrane. Defect size after debridement may be more prognostic for secondary operations rather than the limb segment involved or the degree of soft tissue injury. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Classification of Bone Loss With Failed Stemmed Components in Revision Total Knee Arthroplasty.

With the increasing number of primary total knee arthroplasties (TKA) being performed annually there is also an expected increase in the number of revision TKA, as well as failed revision TKA with stemmed components. A new classification system based upon the location and degree of bone loss in the tibial and or femoral metaphysis and diaphysis is proposed. Type 1 has no bone loss in the metaphysis and diaphysis; Type 2 has a metaphyseal bone loss. Type 3 defects are subdivided into A and B, depending on the extent of the diaphyseal bone loss. Type 4 has extensive bone loss with an expansion of the diaphyseal cortex. An online survey with digital anteroposterior and lateral radiographs was sent to five arthroplasty surgeons. A total of 55 cases with stemmed femoral and tibial components, considered failures and pending revision, were reviewed. By using the proposed classification system, each femoral and tibial component was scored. Interobserver reliability was determined using the intraclass correlation coefficient for pooled data. Comparisons between each individual reviewer demonstrated moderate to strong agreement overall for the reviewers using the classification, with an average correlation coefficient of 0.67 (95% CI [0.57 to 0.77]) for all cases, signifying a low variation in the scores of each case. Looking specifically at the femoral components, the ICC was 0.62 (95% CI [0.477 to 0.76]), while the ICC for the tibial components was 0.71 (95% CI [0.58 to 0.83]). This classification, which has demonstrated moderate to strong interobserver reliability, can help surgeons determine the degree of anticipated bone loss and approach these complex cases with a preoperative plan based upon the radiographic images. This classification system will also allow standardized communication among surgeons, categorization of procedures for comparative research, and anticipated prognosis.

Preliminary Results of the "Capasquelet" Technique for Managing Femoral Bone Defects-Combining a Masquelet Induced Membrane and Capanna Vascularized Fibula with an Allograft.

We describe the preliminary results of a novel two-stage reconstruction technique for extended femoral bone defects using an allograft in accordance with the Capanna technique with an embedded vascularized fibula graft in an induced membrane according to the Masquelet technique. We performed what we refer to as “Capasquelet” surgery in femoral diaphyseal bone loss of at least 10 cm. Four patients were operated on using this technique: two tumors and two traumatic bone defects in a septic context with a minimum follow up of one year. Consolidation on both sides, when achieved, occurred at 5.5 months (4–7), with full weight-bearing at 11 weeks (8–12). The functional scores were satisfactory with an EQ5D of 63.3 (45–75). The time to bone union and early weight-bearing with this combined technique are promising compared to the literature. The osteoinductive role of the induced membrane could play a positive role in the evolution of the graft. Longer follow up and a larger cohort are needed to better assess the implications. Nonetheless, this two-stage technique appears to have ample promise, especially in a septic context or in adjuvant radiotherapy in an oncological context.

A prospective study on outcome of patient-specific cones in revision knee arthroplasty

Cones are known to be good substitutes for metaphyseal and diaphyseal bone loss during revision total knee arthroplasty (RTKA). Often the off-the-shelf cones do not fit to the individual patient's anatomy. New 3D-printing additive technologies allow to develop patient-specific cones. The aim of this prospective study was to describe their outcome. From 2017 until 2020, 35 patient-specific titanium cones (15femoral and 20 tibial) were implanted during 31 RTKAs (45% varus-valgus constrained implants and 55% rotating hinges). Clinical outcome was evaluated using KSS, WOMAC and FJS-12 scoring systems at 12 and 24months. No patients were lost for follow-up. In all cases, there were no technical difficulties in adapting the cones to both the host bone and the revision implant. By the time of performing data analysis (January 2021), none of the 31 patients needed revision surgery for any reason. At 12months of follow-up, the mean values of scores for knee function improved significantly from baseline(p < 0.01): KSS-103.00 (min 100-max 111, SD 5.35), WOMAC-16.5 (min 9-max 24, SD 6.45), FJS-12-61.60 (min 52-max 76, SD 9.20). At 24months, the trend towards improvement of functional results continued but did not reached statistical significance comparing to 12months: KSS was 105.92 (min 95-max 155, SD 16.18), WOMAC-14.07 (min 0-max 42, SD 12.42), FJS-12-83.78 (min 65-max 97, SD 09.64). Radiographic signs of osteointegration were detected within the first 6month after surgery in all cases. Loosening of femoral or tibial components as well as peri-prosthetic infection was not observed in any of the patients during the follow-up. The original additive technology for designing and producing patient-specific metaphyseal and diaphyseal cones with different porosity zones for extensive femoral and tibial bone defects in RTKA is precise and clinically effective solution, at least in the short term. It could be a valid alternative to "off-the-shelf" cones or sleeves as well as structural allografts and even mega-prosthesis, but a longer follow-up period is required to assess its medium- and long-term reliability.

What Is the Reliability of a New Classification for Bone Defects in Revision TKA Based on Preoperative Radiographs?

Accurate quantification of bone loss facilitates preoperative planning and standardization for research purposes in patients who undergo revision TKA. The most commonly used classification to rate bone defects in this setting, the Anderson Orthopaedic Research Institute classification, does not quantify diaphyseal bone loss and reliability has not been well studied. We developed a new classification scheme to rate bone defects in patients undergoing revision TKA and tested (1) the intraobserver and interobserver reliability of this classification for revision TKA based on preoperative radiographs, and (2) whether additional CT images might improve interobserver reliability. This was a preregistered observational study. Interobserver reliability was analyzed using preoperative radiographs of 61 patients who underwent (repeat) revision TKA, and their bone defects were rated by five experienced orthopaedic surgeons. For intraobserver reliability, ratings were repeated at least 2 weeks after the first rating (Timepoints 1 and 2). Directly after the radiographic assessments of Timepoint 2, the observers were provided with CT images of each patient and asked to rate the bone defects for a third time (Timepoint 3), to assess the additional value of CT. Intraobserver and interobserver reliability were tested using Gwet's agreement coefficient 2, which is a measure of agreement between observers in categorical data. Substantial agreement was defined as coefficients between 0.61 to 0.8 and almost perfect agreement as > 0.8. The intraobserver reliability varied between 0.55 (95% CI 0.40 to 0.71) and 0.87 (95% CI 0.78 to 0.96) in the epiphysis, between 0.69 (95% CI 0.58 to 0.80) and 0.98 (95% CI 0.95 to 1) in the metaphysis, and between 0.95 (95% CI 0.90 to 0.99) and 0.99 (95% CI 0.98 to 1) in the diaphysis. The interobserver reliability varied between 0.48 (95% CI 0.39 to 0.57) and 0.49 (95% CI 0.42 to 0.56) in the epiphysis and between 0.81 (95% CI 0.75 to 0.87) and 0.88 (95% CI 0.83 to 0.93) in the metaphysis, and was 0.96 (95% CI 0.93 to 0.99) in the diaphysis at Timepoint 1. The interobserver reliability at Timepoint 2 was similar to that of Timepoint 1. The addition of CT images did not improve reliability (Timepoint 3). The bone defect classification was less reliable in the epiphyseal area compared with the metaphysis and diaphysis. This finding may be explained by prosthetic components obscuring this region or the more severe bone defects in this region. The addition of CT scans did not improve reliability. Further testing of reliability with observers from other institutions is necessary, as well as validity testing, by testing the classification in relation to intraoperative findings. Level III, diagnostic study.

Total Femoral Replacement as a Salvage Operation for the Treatment of Massive Femoral Bone Loss During Revision Total Hip Arthroplasty.

* Revision hip arthroplasty is being performed with increasing frequency in the United States. One of the major challenges during these procedures is addressing associated femoral bone loss.* Varying degrees of proximal metaphyseal and diaphyseal bone loss may be treated with reconstruction techniques involving extensively porous-coated stems, distally based modular stems, and proximal femoral replacement. When diaphyseal bone loss extends beyond the isthmus of the femur with little support for a stem, reconstruction with replacement of the entire femur, hip, and knee (total femoral replacement) may be indicated.* Total femoral replacement is best indicated for older patients with massive loss of bone stock that makes them unsuitable for less-extensive reconstruction methods. The procedure is technically demanding and is associated with a high risk of complications, including major blood loss, deep infection, dislocation, and mechanical implant failure.* In appropriately selected patients, total femoral replacement can provide a successful salvage of an otherwise unreconstructible femur. (Previously, the only options available in such cases were nonoperative treatment, resection arthroplasty, or amputation.) In several case series, total femoral replacement has demonstrated good pain relief and improved function at intermediate to long-term follow-up.

Bone Defect Reconstruction in a 2 Years Old Boy with Non-Vascularized Fibular Graft Using the Induced Membrane Technique in Country with Low-Income: A Case Report

Chronic osteomyelitis in children is frequent in the developing countries. Their complications and morbidity burden the functional prognosis. The reconstruction of diaphyseal bone loss after sequestrectomy in young children remains a difficult and expensive challenge in our context. The delay in care and the lack of social security for all, are risk factors for morbidity. The induced membrane technique described by Masquelet starts to be applied and showed satisfactory results. We report the results of a case of reconstruction of the proximal humerus by using a non-vascularized fibula and supplemental bone substitute in a boy of 2 years with sickle cell. No scarring occurred at the sampling site. The process of bone consolidation is underway.

Long-stemmed humeral components in primary shoulder arthroplasty

Long-stemmed humeral components are often associated with revision shoulder arthroplasty. However, long-stemmed humeral components will likely prove useful in selected patients with extra large shoulders and in those with bone loss from nonarthroplasty causes and in humeral fractures. This study was developed to examine the frequency of use of longer humeral stems, identify the indications for their use, define the results, and enumerate the complications encountered. Thirty-five primary shoulder arthroplasties were followed-up clinically and radiographically for at least 2 years or until revision surgery. The primary indications for use of an intermediate or long stem were a large humeral canal in 18 shoulders and severe preoperative metaphyseal or diaphyseal bone loss in 17. Average clinical follow-up was 6.5 years. Excellent or satisfactory results were achieved in 21 of 35 shoulders. No components met criteria to be considered radiographically at risk for clinical loosening. Intraoperative complications included an unrecognized nondisplaced diaphyseal fracture that later displaced in 1 shoulder. Late complications included deep infection in 1 and fracture nonunion in 1. Intermediate or long-stemmed humeral components proved useful in obtaining a secure distal fit in patients with a large humeral canal or in those with significant proximal bone loss. Worse clinical results were achieved in those with bone loss. Radiographic follow-up shows these components are at a low risk for loosening.

Managing femoral bone loss in revision total hip replacement

If a surgeon is faced with altered lesser trochanter anatomy when revising the femoral component in revision total hip replacement, a peri-prosthetic fracture, or Paprosky type IIIb or type IV femoral bone loss, a modular tapered stem offers the advantages of accurately controlling femoral version and length. The splines of the taper allow rotational control, and improve the fit in femoral canals with diaphyseal bone loss. In general, two centimetres of diaphyseal contact is all that is needed to gain stability with modular tapered stems. By allowing the proximal body trial to rotate on a well-fixed distal segment during trial reduction, appropriate anteversion can be obtained in order to improve intra-operative stability, and decrease the dislocation risk. However, modular stems should not be used for all femoral revisions, as implant fracture and corrosion at modular junctions can still occur.

Metaphyseal and diaphyseal bone loss in the tibia following transient muscle paralysis are spatiotemporally distinct resorption events

When the skeleton is catabolically challenged, there is great variability in the timing and extent of bone resorption observed at cancellous and cortical bone sites. It remains unclear whether this resorptive heterogeneity, which is often evident within a single bone, arises from increased permissiveness of specific sites to bone resorption or localized resorptive events of varied robustness. To explore this question, we used the mouse model of calf paralysis induced bone loss, which results in metaphyseal and diaphyseal bone resorption of different timing and magnitude. Given this phenotypic pattern of resorption, we hypothesized that bone loss in the proximal tibia metaphysis and diaphysis occurs through resorption events that are spatially and temporally distinct. To test this hypothesis, we undertook three complimentary in vivo/μCT imaging studies. Specifically, we defined spatiotemporal variations in endocortical bone resorption during the 3weeks following calf paralysis, applied a novel image registration approach to determine the location where bone resorption initiates within the proximal tibia metaphysis, and explored the role of varied basal osteoclast activity on the magnitude of bone loss initiation in the metaphysis using μCT based bone resorption parameters. A differential response of metaphyseal and diaphyseal bone resorption was observed throughout each study. Acute endocortical bone loss following muscle paralysis occurred almost exclusively within the metaphyseal compartment (96.5% of total endocortical bone loss within 6days). Using our trabecular image registration approach, we further resolved the initiation of metaphyseal bone loss to a focused region of significant basal osteoclast function (0.03mm3) adjacent to the growth plate. This correlative observation of paralysis induced bone loss mediated by basal growth plate cell dynamics was supported by the acute metaphyseal osteoclastic response of 5-week vs. 13-month-old mice. Specifically, μCT based bone resorption rates normalized to initial trabecular surface (BRRBS) were 3.7-fold greater in young vs. aged mice (2.27±0.27μm3/μm2/day vs. 0.60±0.44μm3/μm2/day). In contrast to the focused bone loss initiation in the metaphysis, diaphyseal bone loss initiated homogeneously throughout the long axis of the tibia predominantly in the second week following paralysis (81.3% of diaphyseal endocortical expansion between days 6 and 13). The timing and homogenous nature are consistent with de novo osteoclastogenesis mediating the diaphyseal resorption. Taken together, our data suggests that tibial metaphyseal and diaphyseal bone loss induced by transient calf paralysis are spatially and temporally discrete events. In a broader context, these findings are an essential first step toward clarifying the timing and origins of multiple resorptive events that would require targeting to fully inhibit bone loss following neuromuscular trauma.

Utility and complications of long-stem humeral components in revision shoulder arthroplasty

Currently, there is little information on the benefits and problems associated with long-stem humeral components in shoulder arthroplasty. This study examined the frequency of use, indications, complications, and security of fixation using a long-stem humeral component in revision shoulder arthroplasty. Eighty revision shoulder arthroplasties were monitored clinically for at least 2 years or until repeat revision surgery. The primary indications for use of an intermediate or long stem were proximal bone loss in 40, nonunion in 14, a malpositioned previous stem with bone loss in 10, an acute intraoperative fracture in 7, an acute preoperative periprosthetic fracture in 5, diaphyseal bone loss in 2, and a box-shaped osteotomy to remove a well-fixed stem in 2. Clinical follow-up was an average of 5.9 years, and radiographic follow-up was an average of 4.7 years. Intraoperative complications included fracture removing the previous stem in 5, a cortical perforation in 6, and cement extrusion in 7. Late complications included fracture nonunion in 5, deep infection in 2, and component loosening in 1. One component met criteria to be considered radiographically "at risk" for clinical loosening. Long-stem humeral components are useful to obtain secure fixation in healthy bone in revision shoulder arthroplasty in patients with proximal bone loss, diaphyseal fracture, or a previously malpositioned stem. Complications are frequent, and caution should be taken to avoid intraoperative fractures, distal cortical perforation, or cement extrusion. These components are at low risk for loosening.

A Technique for Decision-Making in Cementless Femoral Revision Hip Arthroplasty

Classification systems for femoral revision of a failed THA fail to address several of the more critical determinants. The aim of the present study was to assess the reliability of a simplified algorithm for decision making during cementless reconstruction for femoral loosening with respect to stem length, stem design and the need for an extended trochanteric osteotomy. Four observers with different levels of clinical experience blindly assessed 40 X-rays of hips scheduled for a femoral revision. Intra-observer and inter-observer reliability of 4 radiographic criteria were assessed: 1) diaphyseal bone loss extension to the isthmus; 2) proximal femoral remodelling; 3) presence of cement; and 4) cortical thickness. Inter-observer agreement relating to the four criteria was good (κ = 0.66) for the extension to isthmus, moderate (κ = 0.57) for proximal femoral remodelling and very good for presence of cement (κ = 1) and cortical thickness (κ = 0.88). Intra-observer agreement was good for extension to isthmus and proximal femoral remodelling and very good for presence of cement and cortical thickness. Based on these criteria, an algorithm has been developed to describe 4 reconstruction options. The algorithm seems reliable for decision making during femoral cementless revision, but research into comparison with intraoperative findings is still required. Level II, Development of diagnostic criteria on consecutive patients.

Results of Revision Total Hip Arthroplasty with Modular, Titanium-Tapered Femoral Stems in Severe Proximal Metaphyseal and Diaphyseal Bone Loss

Evidence supporting modular, tapered stems for severe proximal metaphyseal and diaphyseal bone loss is limited. We report our clinical experience with its use for severely deficient femurs. Of 211 revision total hip arthroplasties (THAs), 18 tapered, modular titanium stems were implanted in Paprosky type III and IV femurs. Clinical data were reviewed for function, stability, structural failure and revision surgery at a mean follow-up of 4.5years. The overall survival rate was 94%. One required revision due to infection and subsidence. The mean subsidence was 3.5mm and the mean pre- and post-operative Harris Hip score was 56 and 79, respectively. In surviving cases, patients achieved satisfactory function and there were no mechanical failures. Modular, tapered stems demonstrated acceptable outcomes for management of severe proximal metaphyseal and diaphyseal defects.

Induced Membranes-A Staged Technique of Bone-Grafting for Segmental Bone Loss

Diaphyseal defects too long to be bridged by cancellous bone graft require complex reconstruction. Distraction osteogenesis requires specialized equipment, has a steep learning curve, and is plagued by attendant pin-site complications and nonunion1,2. Vascularized bone, such as from the fibula, requires microsurgical anastomoses (free), or is limited by pedicle length (pedicled), and has attendant donor-site morbidity (both free and pedicled)1,3. The French technique of bone-grafting within induced membranes, otherwise known as the Masquelet technique, offers a viable alternative with minimal complications4,5. In this technique, a cement spacer is placed in a posttraumatic bone defect. Its presence serves a twofold function of preventing fibrous ingrowth into the bone gap, and inducing the formation of specialized tissue or so-called induced membranes around it. Bone graft placed within this tube of induced membranes incorporates into functioning bone. We present the case of a patient with diaphyseal bone loss and the case of a patient with epimetaphyseal bone loss, both with ongoing bacterial contamination, successfully treated by this procedure. Both patients were informed that data concerning the case would be submitted for publication, and they consented. Case 1. A twenty-year-old woman was struck by an automobile while crossing the road. She sustained an open (Gustilo-IIIB) diaphyseal fracture of the left tibia (AO-OTA 42-C3) with marked loss of the soft-tissue envelope over the medial, anterior, and posterior aspects of the leg6. The wound was debrided on admission, and immobilization was achieved with an external fixator (Fig. 1). Two additional surgical debridements were necessary to ensure complete removal of extensive road debris contamination and to prepare the wound bed for future soft-tissue coverage. The defect was eventually covered with a vascularized rectus abdominis muscle flap six weeks later. Her recovery was …

Revision Total Hip Arthroplasty Using a Fully Porous-Coated Long Stem - a Minimum 5 Years Follow up -

Purpose: We wanted to evaluate the mid-term results of revision total hip arthroplasty using a fully porous-coated long stem. Materials and Methods: A retrospective series of 20 hips in 19 patients who underwent stem revision with a fully porous-coated long stem were evaluated at a mean follow-up of 64.6 months. The causes of revision were aseptic loosening, periprosthetic fracture and infected arthroplasty. Four kinds of implants had previously been used and an additional bone graft procedure had been done in 17 cases. The Harris hip scores, thigh pain, limping and ROM were reported. Radiological changes of the radiolucent signs, subsidence, loosening and the stress shielding signs were evaluated. Results: The Harris hip score improved from an average of 56.5 to 91.9 and the ROMs were satisfactory. The only case with persistent thigh pain showed stable bony ingrowth. No signs of subsidence or loosening of the stem was found in all the cases. There were 2 cases of periprosthetic fracture. None of the patients experienced re-revision surgery. Conclusion: The mid-term results of revision hip arthroplasty using a fully porous coated long stem have demonstrated that it provides a reliable initial fixation with a propensity for stable longevity. It is relatively easy for the techniques, and there is the opportunity to restore the bone stock by bone-grafting procedures with diaphyseal fixation and bypassing a bone defect. Yet alternative techniques may be required for the femur with extensive diaphyseal bone loss. There are some concerns about the technique and the possibility of making a crack in the femur during the operation, which will cause thigh pain at the follow-up. So, only by employing great caution when performing this technique can successful results be guaranteed.

Articular bone loss treated with a staged method using bone cement or beads as a spacer and subsequent autografting: a report of two cases

Fractures with bone loss are rare. Cancellous autografting is commonly used to treat metaphyseal and diaphyseal traumatic bone loss, but little is known about the applicability of this method to the treatment of intra-articular bone loss. We report two cases of articular bone loss that were treated with a staged method of using antibiotic-impregnated bone cement in one case and beads in another as spacer in the primary phase and cancellous autografting in second-stage surgery.

RECOMBINANT HUMAN BMP-2 AND ALLOGRAFT COMPARED WITH AUTOGENOUS BONE GRAFT FOR RECONSTRUCTION OF DIAPHYSEAL TIBIAL FRACTURES WITH CORTICAL DEFECTS

Background: Currently, the treatment of diaphyseal tibial fractures associated with substantial bone loss often involves autogenous bone-grafting as part of a staged reconstruction. Although this technique results in high healing rates, the donor-site morbidity and potentially limited supply of suitable autogenous bone in some patients are commonly recognized drawbacks. The purpose of the present study was to investigate the benefit and safety of the osteoinductive protein recombinant human bone morphogenetic protein-2 (rhBMP-2) when implanted on an absorbable collagen sponge in combination with freeze-dried cancellous allograft. Methods: Adult patients with a tibial diaphyseal fracture and a residual cortical defect were randomly assigned to receive either autogenous bone graft or allograft (cancellous bone chips) for staged reconstruction of the tibial defect. Patients in the allograft group also received an onlay application of rhBMP-2 on an absorbable collagen sponge. The clinical evaluation of fracture-healing included an assessment of pain with full weight-bearing and fracture-site tenderness. The Short Musculoskeletal Function Assessment (SMFA) was administered before and after treatment. Radiographs were used to document union, the presence of extracortical bridging callus, and incorporation of the bone-graft material. Results: Fifteen patients were enrolled in each group. The mean length of the defect was 4 cm (range, 1 to 7 cm). Ten patients in the autograft group and thirteen patients in the rhBMP-2/allograft group had healing without further intervention. The mean estimated blood loss was significantly less in the rhBMP-2/allograft group. Improvement in the SMFA scores was comparable between the groups. No patient in the rhBMP-2/allograft group had development of antibodies to BMP-2; one patient had development of transient antibodies to bovine type-I collagen. Conclusions: The present study suggests that rhBMP-2/allograft is safe and as effective as traditional autogenous bone-grafting for the treatment of tibial fractures associated with extensive traumatic diaphyseal bone loss. Level of Evidence: Therapeutic Level II. See Instructions to Authors for a complete description of levels of evidence.

Recombinant Human BMP-2 and Allograft Compared with Autogenous Bone Graft for Reconstruction of Diaphyseal Tibial Fractures with Cortical Defects

Currently, the treatment of diaphyseal tibial fractures associated with substantial bone loss often involves autogenous bone-grafting as part of a staged reconstruction. Although this technique results in high healing rates, the donor-site morbidity and potentially limited supply of suitable autogenous bone in some patients are commonly recognized drawbacks. The purpose of the present study was to investigate the benefit and safety of the osteoinductive protein recombinant human bone morphogenetic protein-2 (rhBMP-2) when implanted on an absorbable collagen sponge in combination with freeze-dried cancellous allograft. Adult patients with a tibial diaphyseal fracture and a residual cortical defect were randomly assigned to receive either autogenous bone graft or allograft (cancellous bone chips) for staged reconstruction of the tibial defect. Patients in the allograft group also received an onlay application of rhBMP-2 on an absorbable collagen sponge. The clinical evaluation of fracture-healing included an assessment of pain with full weight-bearing and fracture-site tenderness. The Short Musculoskeletal Function Assessment (SMFA) was administered before and after treatment. Radiographs were used to document union, the presence of extracortical bridging callus, and incorporation of the bone-graft material. Fifteen patients were enrolled in each group. The mean length of the defect was 4 cm (range, 1 to 7 cm). Ten patients in the autograft group and thirteen patients in the rhBMP-2/allograft group had healing without further intervention. The mean estimated blood loss was significantly less in the rhBMP-2/allograft group. Improvement in the SMFA scores was comparable between the groups. No patient in the rhBMP-2/allograft group had development of antibodies to BMP-2; one patient had development of transient antibodies to bovine type-I collagen. The present study suggests that rhBMP-2/allograft is safe and as effective as traditional autogenous bone-grafting for the treatment of tibial fractures associated with extensive traumatic diaphyseal bone loss. Therapeutic Level II. See Instructions to Authors for a complete description of levels of evidence.