Bony Hypertrophy in Vascularized Fibular Grafts.

Background: Vascularized fibula graft (VFG) transfer is an established method of repairing large skeletal defects resulting from trauma, tumor resection, or infection. It obviates the process of creeping substitution that conventional bone grafts undergo and therefore exhibits better healing and improved strength. The aim of this study is to evaluate hypertrophy in VFG. Methods: We retrospectively reviewed patients undergoing VFG and studied immediate and late postoperative radiographs. Orthogonal views were measured for width of graft cortex and intramedullary canal, as well as adjacent recipient bone. Changes were measured for total cross sectional area, cortical area, intramedullary area, and graft width. Results: Thirty patients were included in the analysis, with recipient sites including 3 forearm, 4 humerus, 12 tibia, and 11 femur. Mean follow-up was 7.6 years (0.5-24.9 years). Patients' mean age was 31 (16-59 years). Average hypertrophy was 254% in early postoperative period and 340% in the late postoperative period. There was rapid graft hypertrophy in early postoperative period that plateaued with time. The width of the graft increased over time but didn't exceed the width of the adjacent recipient bone. In the later postoperative period, the size of graft intramedullary canal increased. Upper and lower extremity grafts showed similar hypertrophy. Conclusions: Using VFG to treat large skeletal defects is an attractive option in part due to the graft's ability to hypertrophy. We describe an early period of periosteal hypertrophy, followed by endosteal hypertrophy. These processes have relevance to function, mechanical strength, and surgical decision-making.

Naringin inhibits titanium particles-induced up-regulation of TNF-α and IL-6 via the p38 MAPK pathway in fibroblasts from hip periprosthetic membrane.

AIMS: Inflammatory responses to wear debris cause osteolysis that leads to aseptic loosening and hip arthroplasty failure. Wear debris stimulate macrophages and fibroblasts to secret proinflammatory cytokines, including TNF-α and IL-6, which have been specifically implicated in periprosthetic osteolysis and osteoclast differentiation. Naringin has anti-inflammatory effect in macrophages. Moreover, naringin inhibited osteoclastogenesis and wear particles-induced osteolysis. In this study, we examined the potential inhibitory effects of naringin on titanium (Ti) particle-induced proinflammatory cytokines secretion in fibroblasts and the possible underlying molecular mechanisms. MATERIALS AND METHODS: Fibroblasts were isolated from periprosthetic membrane at the time of revision surgery performed due to aseptic loosening after hip arthroplasty and were cultured in the presence or absence of Ti particles, naringin and mitogen-activated protein kinase (MAPK) inhibitors, PD98059 (a selective inhibitor of ERK), SP600125 (a selective inhibitor of JNK), and SB203580 (a selective inhibitor of p38). TNF-α and IL-6 assays were performed using enzyme-linked immunosorbent assay kits. The phosphorylation levels of p38 and nuclear factor kappa B p65 (NF-κB p65) were examined by western blot. RESULTS: Naringin or SB203580 pretreatment significantly suppressed the secretion of TNF-α and IL-6 induced by titanium particles in fibroblasts, while inhibition of ERK or JNK pathways showed no effect on production of TNF-α and IL-6. Moreover, naringin inhibited Ti particle-induced phosphorylation of p38 and p65. CONCLUSIONS: These results indicated that naringin could inhibit Ti particle-induced inflammation in fibroblasts by inhibiting p38 MAPK/NF-κB p65 activity and might be a potential drug for the treatment of inflammatory periprosthetic osteolysis after arthroplasty.

Naringin increases osteoprotegerin expression in fibroblasts from periprosthetic membrane by the Wnt/ß-catenin signaling pathway.

BACKGROUND: The osteoclast bone resorption is critical in aseptic loosening after joint replacement. The balance between activator of nuclear factor kappa B ligand (RANKL) and osteoprotegerin (OPG) is considered to play a central role in osteoclast maturation. Fibroblasts from the periprosthetic membrane express RANKL and promote osteoclast formation. Studies have demonstrated that naringin inhibited osteoclastogenesis and wear particle-induced osteolysis. In this study, the naringin-induced OPG/RANKL effects and its underlying mechanism were studied in fibroblasts from periprosthetic membrane. METHODS: Fibroblasts were isolated from the periprosthetic membrane during hip arthroplasty for revision due to aseptic loosening. Fibroblasts were cultured and treated with or without naringin and DKK-1 (the classical inhibitor of Wnt/ß-catenin signaling pathway). OPG and RANKL mRNA and protein levels, gene expression of ß-catenin, and cyclin D1, which participate in the Wnt signaling pathway, were examined by real-time polymerase chain reaction and enzyme-linked immunosorbent assay. RESULTS: The mRNA and protein levels of OPG were enhanced by naringin in a dose-dependent manner compared to that of the non-treated control. In contrast, naringin did not affect the expression of RANKL. Importantly, DKK-1 attenuated OPG expression in fibroblasts under naringin treatment. Moreover, naringin stimulated the gene expression of ß-catenin and cyclin D1 in fibroblasts, and the effect could be inhibited by DKK-1. CONCLUSION: The results indicated that naringin enhanced OPG expression through Wnt/ß-catenin signaling pathway in fibroblasts from periprosthetic membrane, which may be useful to inhibit periprosthetic osteolysis during aseptic loosening after total joint arthroplasty.

Limb salvage for malignant bone tumours of distal tibia with dual ipsilateral vascularized autogenous fibular graft in a trapezoid-shaped array with ankle arthrodesis and preserving subtalar joint.

BACKGROUND: The treatment of malignant tumours of the distal tibia is a challenging surgical problem due to the scarce soft tissue coverage and the instability of the ankle joint that often occurs after resection. However, there is no consensus on the ideal treatment for malignant tumours of the distal tibia. METHODS: We report a new reconstruction for five patients with high-grade osteosarcoma of distal tibia, using dual ipsilateral vascularized autogenous fibular graft in a trapezoid-shaped array and external fixator, with ankle arthrodesis and preserving subtalar joints. The patients were examined clinically and radiographically. RESULTS: The average follow-up duration was 88 months. The mean wound healing time was 14 days. Bone healing was achieved for all the five patients at an average time of 7 months. There were no complications of mal-union, skin necrosis, post-operative infection, loss of internal fixation, peroneal nerve injury. One patient had a local recurrence, which required amputation 15 months postoperatively. The remaining four patients were able to walk with an average functional score of 81.25% according to MSTS. CONCLUSIONS: Our study shows that this technique is safe and effective to perform implantation of dual ipsilateral vascularized autogenous fibular graft in a trapezoid-shaped array and preserving subtalar joints in terms of the distal tibial reconstruction for malignant bone tumour of the distal tibia. This reconstruction represents a biological alternative protocol for limb salvage in cases of malignant bone tumour of the distal tibia, with encouraging results and with the advantages of lower complications and accelerating recovery. LEVEL OF EVIDENCE: Level IV.

A prospective study of coracoclavicular ligament reconstruction with autogenous peroneus longus tendon for acromioclavicular joint dislocations.

BACKGROUND: Anatomic coracoclavicular (CC) ligament reconstruction (ACCR) provides good outcomes for Rockwood type III and VI acromioclavicular (AC) joint dislocations. Various grafts have been used, but complications from graft harvesting are not uncommon. This study examined the clinical and radiographic outcomes of patients with AC joint dislocations repaired with the autogenous anterior half of the peroneus longus tendon (AHPLT) to achieve ACCR. METHODS: Patients with a Rockwood type III to V AC joint dislocation and magnetic resonance imaging of the disruption of the CC ligaments, as well as the AC capsule, were prospectively recruited. Patients received ACCR using an autogenous AHPLT graft and were evaluated clinically and radiographically preoperatively and at 1, 3, 6, and 12 months postoperatively. RESULTS: A total of 18 patients (mean age, 51 years) were prospectively recruited and received an autogenous AHPLT graft ACCR. Fifteen patients completed clinical and radiographic follow-up examinations at 12 months. The mean Constant score (CS) was 51 preoperatively and 93 at 12 months (P <.005). No significant difference was noted at 12 months between the CS of the injured and contralateral shoulder. The mean American Orthopedic Foot and Ankle Society score at 12 months was 99, and this was not different from the value at any other time point. Loss of reduction occurred in 10 patients (56%), and tunnel widening was observed in 9 (50%), but neither was significantly correlated with functional outcome. CONCLUSION: Autogenous AHPLT appears to be a reliable tendon graft source for CC ligament reconstruction.

Evaluation of 2-stage Treatment for Cervical Dorsal Rami Entrapment Syndrome: A Randomized, Controlled Trial.

OBJECTIVES: To evaluate the effectiveness of a 2-stage nonoperative treatment for patients with cervical dorsal rami entrapment syndrome. MATERIALS AND METHODS: The study included 66 patients diagnosed with cervical dorsal rami entrapment syndrome randomized to an experimental group (n=33) and control group (n=33). The experimental group was treated with additional diagnostic block if regular 2 weeks medication was not effective. The control group only received nonsteroidal anti-inflammatory drugs for 2 weeks. A visual analog scale (VAS) and pain treatment satisfaction scale (PTSS) were used to assess pain. Muscle power in the upper limbs was also assessed. The registration number of this study is ChiCTR-IIR-15007565. RESULTS: The VAS scores of the experimental group were significantly lower at 2, 4, and 6 months after treatment compared with baseline and the VAS scores of the control group (all P<0.001). The PTSS scores of the experimental group were significantly higher at 2, 4, and 6 months after treatment compared with baseline and the PTSS scores of the control group (all P<0.001). Maximal muscle power after treatment was significantly greater in the experimental group compared with the control group for shoulder abduction (P<0.001), thumb pinch force (P=0.001), and grasp (P<0.001). CONCLUSIONS: The results suggest that the 2-stage treatment is effective for patients with cervical dorsal rami entrapment syndrome.

Femoral neck shortening in adult patients under the age of 55 years is associated with worse functional outcomes: Analysis of the prospective multi-center study of hip fracture outcomes in China (SHOC).

INTRODUCTION: Young femoral neck fracture patients require surgical fixation to preserve the native hip joint and accommodate increased functional demands. Recent reports have identified a high incidence of fracture shortening and this may have negative functional consequences. We sought to determine if fracture shortening is associated with poor functional outcome in young femoral neck fracture patients. PATIENTS AND METHODS: One hundred and forty-two patients with femoral neck fractures age 18-55 were recruited in this prospective cohort study across three Level 1 trauma hospitals in Mainland China. Patient-reported and objective functional outcomes were measured with the Harris Hip Score (HHS), Timed Up and Go (TUG), and SF-36 Physical Component Summary (SF-36 PCS) at 12 months. Radiographic fracture shortening was measured along the long axis of the femoral neck and corrected for magnification. Severe shortening was defined as ≥10mm. The primary analysis measured associations between severe radiographic shortening and HHS at one-year post-fixation. RESULTS: One hundred and two patients had complete radiographic and functional outcomes available for analysis at one year. The mean age of participants was 43.7±10.8years and 53% were male. Fifty-five percent of fractures were displaced and 37% were vertically orientated (Pauwels Type 3). The mean functional outcome scores were: HHS 90.0±10.8, TUG 12.0±5.1s, and PCS 48.5±8.6. Severe shortening occurred in 13% of patients and was associated with worse functional outcome scores: HHS mean difference 9.9 (p=0.025), TUG mean difference 3.2s (p=0.082), and PCS mean difference 5.4 (p=0.055). CONCLUSIONS: Severe shortening is associated with clinically important decreases in functional outcome as measured by HHS following fixation of young femoral neck fractures, occurring in 13% of patients in this population. The principle of fracture site compression utilized by modern constructs may promote healing; however, excessive shortening is associated with worse patient-reported outcomes and objective functional measures.

Femoral Neck Fractures in Adults Treated With Internal Fixation: A Prospective Multicenter Chinese Cohort.

INTRODUCTION: Although femoral neck fractures in young patients are rare and their complications are well-documented, there is a paucity of data on patient-reported outcomes for this population. The purpose of this study was to describe the quality of life and the effect of clinical complications on the outcomes of young patients with femoral neck fractures in a Chinese cohort. METHODS: In this prospective observational cohort study, patients aged 18 to 55 years admitted to one of three participating trauma hospitals in China for treatment of a femoral neck fracture were recruited. The primary outcome was the patient's health-related quality of life using the Medical Outcomes Study 36-Item Short Form (SF-36) Health Survey at 1 year after injury. Associations between the primary outcome and potential predictors were explored with univariate and multivariate regression analysis. RESULTS: One hundred seven patients (mean age, 44 years) completed 1-year follow-up. Nearly all patients were treated with closed reduction and screw fixation. Nine cases of nonunion, 7 cases of malunion, and 11 cases of osteonecrosis were identified. The mean SF-36 Physical Component Score was 48.6 ± 8.5, and the mean Mental Component Score was 51.0 ± 7.4. Fracture displacement, quality of reduction, and nonunion were associated with a poor Physical Component Score outcome. DISCUSSION: Our results demonstrate that the quality of life for patients after closed reduction and screw fixation of femoral neck fractures is similar to that of the general population, particularly when complications of nonunion and malunion are avoided. LEVEL OF EVIDENCE: Level I.

A histomorphometric study of necrotic femoral head in rabbits treated with extracorporeal shock waves.

[Purpose] This study aimed to determine the effectiveness and mechanisms of extracorporeal shock wave therapy in the treatment of femoral head osteonecrosis. [Subjects and Methods] Histomorphometric analysis of necrotic femoral head in rabbits treated with shock waves was performed. Bilateral osteonecrosis of femoral heads was induced with methylprednisolone and lipopolysaccharide in eight rabbits. The left limb (study side) received shock waves to the femoral head. The right limb (control side) received no shock waves. Biopsies of the femoral heads were performed at 12 weeks after shock wave therapy. [Results] Necrotic femoral heads treated with shock waves, compared with controls, had higher bone volume per tissue volume, trabecular thickness, trabecular number, osteoblast surface/bone surface, osteoid surface/bone surface, osteoid thickness, mineralizing surface/bone surface, mineralizing apposition rate, and bone formation rate. However, trabecular separation was lower in shock wave-treated femoral heads than in controls. Eroded surface/bone surface and osteoclast surface/bone surface did not differ significantly between groups. [Conclusion] The bone mass of necrotic femoral heads treated with shock waves increases. Extracorporeal shock wave may promote bone repair in necrotic femoral heads through the proliferation and activation of osteoblasts.

Surgical treatment of severe multilevel circumferential compressive myelopathy of the cervical spine: is circumferential procedure necessary?

OBJECTIVE: To determine the necessity of circumferential decompression and fusion in patients with severe multilevel cervical spondylotic myelopathy with circumferential cord compression. METHODS: This prospective study involved 51 patients with severe multilevel circumferential cervical myelopathy underwent two-stage circumferential procedure between July 2008 and June 2010. VAS scores, satisfaction surveys and JOA scores and imaging studies were obtained. Twenty-three patients (45.1%) underwent two-stage surgery (group A); the other 28 patients (54.9%) were satisfied with the outcomes after first-stage surgery, and the second-stage surgery was avoided (group B). Age, sex and symptom duration did not differ between the groups. RESULTS: Patients were followed up for 3-5 years (mean, 42.5 months). In group A, VAS and JOA scores significantly improved from 63.3 and 7.9 to 38.3 and 10.4, respectively, at 3 months after the first-stage operation and 10.2 and 12.7, respectively, at 3 months after the second-stage operation. In group B, the VAS and JOA scores significantly improved from 62.7 and 7.9 to 31.1 and 11.2 respectively, at 3 months and 18.2 and 12.4, respectively at 6 months. Patient satisfaction rate significantly increased from 43.5% after the first-stage operation to 82.6% after the second-stage operation in group A. In group B, this rate was 89.3%. In group A, cervical spine lordosis increased from 12.8° preoperatively to 18.5° (p < .0001) and 19.1° (p > .05) at 3 months after the first-stage and second-stage operations, respectively. In group B, lordosis significantly increased from 12.5° preoperatively to 18.8° at 3 months. The total complication rate did not significantly differ from the rates after a single surgery (either anterior or posterior). CONCLUSION: Only 45.1% patients required surgery via both approaches. Therefore, a two-stage procedure is a rational choice and safe procedure. If outcomes are unsatisfactory after the first-stage operation, a second-stage operation can be performed.

Reverse polyaxial less invasive stabilization systems for treatment of femoral intertrochanteric fractures of the distal femur.

INTRODUCTION: The reverse less invasive stabilization system (LISS) for the distal femur remains generally regarded as a safe and satisfactory option for the treatment of unstable proximal femoral fractures. The polyaxial LISS provides a reverse plating technique that leverages the advantages of proximal screws by allowing the adjustable locking screw to be better positioned and providing more reliable fixation on the proximal femur compared with the standard axial LISS. To assess this fixation method, a detailed evaluation of institutional outcomes of femoral intertrochanteric fractures treated with reverse polyaxial LISS was performed. MATERIALS AND METHODS: A total of 29 patients presenting with femoral intertrochanteric fractures were treated with the reverse polyaxial LISS system between January 2010 and March 2011. Patients were classified into stable and unstable fracture groups according to the Orthopaedic Trauma Association's (OTA) classification. Clinical data, including operative time, blood loss, radiological records and complications, Harris Hip scores and Parker scores, were collected and analyzed. RESULTS: There were no significant between-group differences in age, sex, or American Society of Anesthesiologists score. Operative time and blood loss were significantly higher in the unstable fracture group compared with the stable fracture group. Four cases of fixation failure, consisting of one case of A2.3, one case of A3.2 and two cases of A3.3, occurred 4-7 m postoperatively. CONCLUSIONS: Treatment of femoral intertrochanteric fractures with unstable pattern using polyaxial reverse LISS results in high failure rates; therefore, it should not be recommended as a routine alternative method for the treatment of femoral intertrochanteric fractures with unstable pattern.

Percutaneous Vertebroplasty Versus Conservative Treatment in Aged Patients With Acute Osteoporotic Vertebral Compression Fractures: A Prospective Randomized Controlled Clinical Study.

STUDY DESIGN: A prospective randomized clinical trial. OBJECTIVE: In this study, we determine whether percutaneous vertebroplasty (PVP) offers extra benefits to aged patients with acute osteoporotic vertebral compression fractures (OVCFs) over conservative therapy (CV). SUMMARY OF BACKGROUND DATA: OVCFs are common in the aged population with osteoporosis. While the optimal treatment of aged patients with acute OVCFs remains controversial, PVP, a minimally invasive procedure, is a treatment option to be considered. METHODS: Patients aged at 70 years or above with acute OVCF and severe pain from minor or mild trauma were assigned randomly to PVP and CV groups. The primary outcome was pain relief as measured by VAS score in 1-year follow-up period. The second outcome was quality of life assessed with ODI and Quality of Life Questionnaire of the European Foundation for Osteoporosis (QUALEFFO). Patient satisfaction surveys were also recorded. RESULTS: A total of 135 patients were enrolled, and 107 (56 in PVP group; 51 in CV group) completed 1-year follow-up. In PVP group, the vertebroplasty procedure was performed at a mean of 8.4 ±â€Š4.6 days (range, 2-21 days) after onset. Vertebroplasty resulted in much greater pain relief than did conservative treatment at postoperative day 1 (P < 0.0001). At every time point of follow-up, pain relief and quality of life were significantly improved in PVP group than in CV group at 1 week, 1 month, 3 months, 6 months, and 1 year (all P < 0.0001). The final follow-up surveys indicated that patients in PVP group were significantly more satisfied with given treatment (P < 0.0001). In addition, lower rate of complications was observed in PVP group (P < 0.0001). CONCLUSION: In aged patients with acute OVCF and severe pain, early vertebroplasty yielded faster, better pain relief and improved functional outcomes, which were maintained for 1 year. Furthermore, it showed fewer complications than conservative treatment. LEVEL OF EVIDENCE: 2.

An RCT study comparing the clinical and radiological outcomes with the use of PLIF or TLIF after instrumented reduction in adult isthmic spondylolisthesis.

OBJECTIVE: We prospectively compared posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion (TLIF) used in adult isthmic spondylolisthesis (IS) after surgical reduction with pedicle screws. METHODS: Between January 2009 and December 2010, 66 adult patients with single-level IS were randomly assigned to two groups treated using the PLIF technique (PLIF group, n = 34) and the TLIF technique (TLIF group, n = 32). Both groups were followed up for an average of 30.5 months (range 24-48 months). Clinical outcomes were assessed using the visual analog scale (VAS), Oswestry disability index (ODI) and Japanese orthopedic association (JOA) scores. Radiographic outcomes included percentage of vertebral slippage, focal lordosis and disk height. Clinical and radiographic outcomes were compared between the two groups. RESULTS: The average operative time and blood loss during surgery were significantly more in PLIF group than in TLIF group. Spondylolisthesis, disk height and focal lordosis were significantly improved postoperatively in both groups. There was no obvious difference in clinical outcomes, as assessed using the VAS, ODI and JOA scores, and radiographic outcomes. In PLIF group, there were two cases of neuropathic pain after surgery. CONCLUSIONS: After instrumented reduction of adult IS, either PLIF or TLIF can provide good clinical and radiological outcomes. With a single cage, TLIF was superior to PLIF in terms of surgical time and blood loss, but these differences may not be clinically relevant.

Alendronate stimulates osteoprotegerin expression in fibroblasts from periprosthetic membrane.

PURPOSE: Aseptic loosening of an implant after total joint arthroplasty is still a major complication that results from periprosthetic osteolysis. Fibroblasts in the interface membrane express receptor activator of nuclear factor kappa B ligand (RANKL) and stimulate osteoclast formation. Studies demonstrate that through the control of osteoclastic bone loss bisphosphonates inhibit wear particle-induced bone resorption around total hip arthroplasty. The majority of bisphosphonates studies have focused on their effects on osteoblasts and osteoclasts. Little attention has been paid to their action on fibroblasts. METHODS: We isolated fibroblasts from the interface membrane that was obtained when revision hip arthroplasty was performed because of aseptic loosening. Fibroblasts were stimulated with alendronate. RANKL and osteoprotegerin (OPG) assays were performed using enzyme-linked immunosorbent assay kit and real time Reverse Transcription- Polymerase Chain Reaction (RT-PCR). RESULTS: We found that alendronate stimulated OPG mRNA and protein expression in a time and dose dependent manner. By contrast, alendronate did not affect RANKL expression. CONCLUSIONS: The results indicate that alendronate modulated OPG production by fibroblasts from periprosthetic membrane, which may prove helpful for the inhibition of bone loss during aseptic loosening following total joint arthroplasty.

Titanium Elastic Nail (TEN) versus Reconstruction Plate Repair of Midshaft Clavicular Fractures: A Finite Element Study.

BACKGROUND: The biomechanical characteristics of midshaft clavicular fractures treated with titanium elastic nail (TEN) is unclear. This study aimed to present a biomechanical finite element analysis of biomechanical characteristics involved in TEN fixation and reconstruction plate fixation for midshaft clavicular fractures. METHODS: Finite element models of the intact clavicle and of midshaft clavicular fractures fixed with TEN and with a reconstruction plate were built. The distal clavicle displacement, peak stress, and stress distribution on the 3 finite element models were calculated under the axial compression and cantilever bending. RESULTS: In both loading configurations, TEN generated the highest displacement of the distal clavicle, followed by the intact clavicle and the reconstruction plate. TEN showed higher peak bone and implant stresses, and is more likely to fail in both loading configurations compared with the reconstruction plate. TEN led to a stress distribution similar to that of the intact clavicle in both loading configurations, whereas the stress distribution with the reconstruction plate was nonphysiological in cantilever bending. CONCLUSIONS: TEN is generally preferable for treating simple displaced fractures of the midshaft clavicle, because it showed a stress distribution similar to the intact clavicle. However, TEN provides less stability, and excessive exercise of and weight bearing on the ipsilateral shoulder should be avoided in the early postoperative period. Fixation with a reconstruction plate was more stable but showed obvious stress shielding. Therefore, for patients with a demand for early return to activity, reconstruction plate fixation may be preferred.

The mechanical benefit of medial support screws in locking plating of proximal humerus fractures.

BACKGROUND: The purpose of this study was to evaluate the biomechanical advantages of medial support screws (MSSs) in the locking proximal humeral plate for treating proximal humerus fractures. METHODS: Thirty synthetic left humeri were randomly divided into 3 subgroups to establish two-part surgical neck fracture models of proximal humerus. All fractures were fixed with a locking proximal humerus plate. Group A was fixed with medial cortical support and no MSSs; Group B was fixed with 3 MSSs but without medial cortical support; Group C was fixed with neither medial cortical support nor MSSs. Axial compression, torsional stiffness, shear stiffness, and failure tests were performed. RESULTS: Constructs with medial support from cortical bone showed statistically higher axial and shear stiffness than other subgroups examined (P<0.0001). When the proximal humerus was not supported by medial cortical bone, locking plating with medial support screws exhibited higher axial and torsional stiffness than locking plating without medial support screws (P ≤ 0.0207). Specimens with medial cortical bone failed primarily by fracture of the humeral shaft or humeral head. Specimens without medial cortical bone support failed primarily by significant plate bending at the fracture site followed by humeral head collapse or humeral head fracture. CONCLUSIONS: Anatomic reduction with medial cortical support was the stiffest construct after a simulated two-part fracture. Significant biomechanical benefits of MSSs in locking plating of proximal humerus fractures were identified. The reconstruction of the medial column support for proximal humerus fractures helps to enhance mechanical stability of the humeral head and prevent implant failure.

Continuous irrigation and drainage for early postoperative deep wound infection after posterior instrumented spinal fusion.

STUDY DESIGN: A retrospective study of clinical cases. PURPOSE: To evaluate the efficacy of continuous irrigation and drainage for early postoperative deep wound infection after posterior instrumented spinal fusion. SUMMARY OF BACKGROUND DATA: Aggressive debridement and irrigation has been recommended to treat postoperative wound infections after instrumented spinal fusion. However, this method of management, indicating repeating visits to the operating room until the wound is clean enough for closure, often results in prolonged hospitalization, increased cost, and sometimes compromise of the desired outcome. We hypothesize that repeat visits to the operating room for debridements can be avoided by aggressive debridements and primary closure with continuous irrigation and drainage for postoperative wound infections. METHODS: From 2004 to 2009, 23 patients with early postoperative deep wound infections after spinal fusion with instrumentation were surgically treated with thorough debridement and primary closure with continuous irrigation and drainage. All patients were followed up for 30.6 months (range, 24-54 mo). RESULTS: The mean duration of irrigation was 12.0 days (range, 7-16 d). In 21 patients (91.3%), the wound healed after continuous irrigation. The removal of the instrumentation or cages was not required in any case. Spinal fusion was achieved in all cases, except 1, where the patient developed a pseudoarthrosis at the L4-L5 level after L4-S1 fusion. The mean ODI for these 23 patients improved significantly from 53.4±18.7 preoperatively to 18.3±11.2 at the final follow-up visit (P<0.001). The mean JOA scores increased significantly from 15.5±4.1 preoperatively to 24.3±3.8 at the final follow-up (P<0.001). CONCLUSIONS: Continuous irrigation and drainage is an effective and safe method for the treatment of early postoperative deep wound infection after posterior instrumented spinal fusion.

Identification of duplication downstream of BMP2 in a Chinese family with brachydactyly type A2 (BDA2).

Brachydactyly type A2 (BDA2, MIM 112600) is characterized by the deviation and shortening of the middle phalange of the index finger and the second toe. Using genome-wide linkage analysis in a Chinese BDA2 family, we mapped the maximum candidate interval of BDA2 to a ∼1.5 Mb region between D20S194 and D20S115 within chromosome 20p12.3 and found that the pairwise logarithm of the odds score was highest for marker D20S156 (Zmax = 6.09 at θ = 0). Based on functional and positional perspectives, the bone morphogenetic protein 2 (BMP2) gene was identified as the causal gene for BDA2 in this region, even though no point mutation was detected in BMP2. Through further investigation, we identified a 4,671 bp (Chr20: 6,809,218-6,813,888) genomic duplication downstream of BMP2. This duplication was located within the linked region, co-segregated with the BDA2 phenotype in this family, and was not found in the unaffected family members and the unrelated control individuals. Compared with the previously reported duplications, the duplication in this family has a different breakpoint flanked by the microhomologous sequence GATCA and a slightly different length. Some other microhomologous nucleotides were also found in the duplicated region. In summary, our findings support the conclusions that BMP2 is the causing gene for BDA2, that the genomic location corresponding to the duplication region is prone to structural changes associated with malformation of the digits, and that this tendency is probably caused by the abundance of microhomologous sequences in the region.

Morphological measurements of the posterior surface of the normal proximal tibia in a healthy Chinese population.

BACKGROUND: To measure and calculate the morphological parameters and determine the anatomical characteristics of the posterior surface of the proximal tibia in a healthy Chinese population. METHODS: A total of 150 volunteers with normal knees were enrolled. The parameters in the multi-slice spiral computed tomography (MSCT) three-dimensional (3-D) reconstruction images were measured and calculated by two independent qualified observers. The differences and correlation were investigated. The intraclass correlation coefficient (ICC) was used to assess inter-observer reliability. RESULTS: The posterior margin of the tibial plateau is presented as two superior arc-shapes. The central angles of these arcs were 118°±14° (medial) and 106°±20° (lateral). The radii of these arcs both showed a skewed distribution. The median radii of the arcs were 22 mm in the medial and 20mm in the lateral. There were two significant angles present in the sagittal plane of the posterior cortex of the proximal tibia. The first angles were 39°±7° (medial) and 47°±7° (lateral). The second angles were 39°±4° (medial) and 41°±5° (lateral). Significant differences were observed in the central angles and the first angles but not in the second angles between the medial and lateral. There were no significant differences between different gender groups, and between left and right limbs. All of these parameters exhibited excellent to moderate ICC. CONCLUSION: Due to the varying anatomic morphology between the postero-medial and postero-lateral surface of the proximal tibia, the internal fixation implants of these two parts should be designed differently.

Single segment of posterior lumbar interbody fusion for adult isthmic spondylolisthesis: reduction or fusion in situ.

OBJECTIVE: We prospectively compared surgical reduction or fusion in situ with posterior lumbar interbody fusion (PLIF) for adult isthmic spondylolisthesis in terms of surgical invasiveness, clinical and radiographical outcomes, and complications. METHODS: From January 2006 to June 2008, 88 adult patients with isthmic spondylolisthesis who underwent surgical treatment in our unit were randomized to reduced group (group 1, n = 45) and in situ group (group 2, n = 43), and followed up for average 32.5 months (range 24-54 months). The clinical and radiographical outcomes were compared between the two groups. RESULTS: The average operative time and blood loss during surgery showed insignificant difference (p > 0.05) between two groups. The radiological outcomes were significantly better in group 1, but there was no significant difference between two groups of clinical outcomes, depicting as VAS, ODI, JOA and patients' satisfaction surveys. Incident rate of surgical complications was similar in two groups, but in group 1 the complication seemed more severe because of two patients with neurological symptoms. CONCLUSIONS: For the adult isthmic spondylolisthesis without degenerative disease in adjacent level, single segment of PLIF with pedicle screw fixation is an effective and safe surgical procedure regardless of whether additional reduction had been conducted or not. Better radiological outcome does not mean better clinical outcome.