Effect of ErhBMP-2-loaded β-tricalcium phosphate on ulna defects in the osteoporosis rabbit model

Purpose

Autografts, the gold standard treatment for large bone defects, present complications, especially in conditions with reduced bone-repair capacity, such as osteoporosis. Escherichia coli-derived recombinant human bone morphogenesis protein-2 (ErhBMP-2), was used in this study to improve the osteoinductivity of β-tricalcium phosphate (β-TCP). This study evaluated the bone-repair capacity of ErhBMP-2-loaded β-TCP on osteoporosis rabbit model, relative to the sole use of autograft and β-TCP treatments.

Methods

The osteoporosis rabbit model was induced through ovariectomy and glucocorticoid dosing; 2-cm segmental ulnar defects were created, which were treated with either autograft, β-TCP alone, or ErhBMP-2-loaded β-TCP or left untreated. The quality of newly formed ulnae was evaluated 8 weeks after ulnar surgery through micro-CT, biomechanical, histological, and histomorphometric assessments.

Results

The osteoporosis rabbit model was developed and maintained till the end of the study. The maximal load and stiffness in the ErhBMP-2-loaded TCP group were significantly higher than those in the autograft group, whereas the TCP-alone group performed similarly as did the untreated group in the force loading and stiffness tests. According to the micro-CT evaluation, the ErhBMP-2-loaded TCP group had significantly higher bone volume relative to the autograft and TCP-alone groups. Histological assessments revealed better defect bridging and marrow formation in the ErhBMP-2-loaded TCP group relative to the TCP-alone group. Mineral apposition rates were significantly higher in the ErhBMP-2-loaded TCP and autograft groups than in the TCP-alone and untreated groups.

Conclusion

Relative to autografts, ErhBMP-2-loaded TCP, as an alternative grafting material, provides better or comparable healing on critical-sized long bone defects in the osteoporosis rabbit model.

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Erh-BMP-2 promoted the bone healing ability of β-TCP in osteoporosis animal model.

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New bone generated by Erh-BMP-2-loaded β-TCP was stiffer than that generated by autograft.

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ErhBMP-2-loaded TCP potentially being an alternative grafting material relative to autograft.

Inhibition of nitric oxide can ameliorate apoptosis and modulate matrix protein gene expression in bacteria infected chondrocytes in vitro

Bacterial infection stimulates nitric oxide (NO) production in chondrocytes. However, the role of NO in chondrocyte apoptosis after infection remains unclear. The purpose of the study was to test if inhibition of NO could ameliorate apoptosis and modulate matrix protein gene expression in bacteria-infected chondrocytes. It was shown that pre-treating chondrocytes with L-NAME (1 mM) significantly decreased the release of NO (from 72 to 14 microM) and the extent of apoptosis (from 52.9% to 18.9%). Pre-treatment with L-NAME also counteracted the bacteria-induced downregulation of Type II collagen (from 26% to 79%) and aggrecan (from 63% to 105%) mRNA levels. Inhibition of NO after the induction of infection could not decrease the extent of apoptosis and modulate matrix protein gene expression. The results of this study support the hypothesis that NO has an important role in bacteria-induced chondrocyte apoptosis. Pre-treatment but not post-treatment could ameliorate the extent of apoptosis and reestablish the cartilage matrix protein gene expression. This study suggests that in addition to NO, other mechanisms may be responsible for the sustained destruction of articular cartilage in the post-infectious arthropathy.

Reconstruction of posttraumatic long bone defect with free vascularized bone graft: good outcome in 48 patients with 6 years' follow-up

We analyzed our clinical results in 48 patients (40 men) treated during 1990-1993 with free vascularized bone-graft reconstruction for bone defects, the follow-up being an average 6 (5-8) years. The bone defects were located in the femur (10), tibia (32), humerus (2), and forearm (4). We performed 41 fibula transfers, 4 iliac transfers, and 3 rib transfers in these patients. 3 patients required early revision surgery due to venous thrombosis. The average time needed for radiographic bone union was 4.2 months. Bone transfers to the lower extremity showed significantly more hypertrophy than those in the upper extremity. The functional outcome was good in 43 patients.

Arthroscopy in avulsion fracture of posterior cruciate ligament

BACKGROUND

Surgical reduction of PCL avulsion fracture was performed from posterior approach and arthroscopic treatment was not routinely performed. However, associated intraarticular lesions of meniscus, cartilage, of any other pathologies were very common in PCL injuries. If the treatments of associated intraarticular lesions would improve the results was not known. Under this prospective study, we want to know if arthroscope is valuable in PCL avulsion fractures.

METHODS

From January 1995 to December 1997, there were 29 cases of PCL avulsion fractures. They were grouped according to chart numbers. Group I was even number group and group II was odd number group. Arthroscopic examination was performed in even number group, but not in odd number group. Group I had 13 cases and group II had 16 cases. All the PCL avulsion fractures were repaired from posterior approach and fixed with cancellous screws.

RESULTS

The range of motion, arthrometric data, and Lysholm score were similar in both group after more than 2 years of follow-up. The residual pain was less in arthroscopic group. Arthroscopic examination showed hemarthrosis in all cases of group I; meniscal lesion in 7 cases (54%), osteochondral or chondral lesions in 3 cases (23%), hard medial plica in 3 cases (23%), patellofemoral lesion in 1 case (7.7%), ACL tear in 1 case (7.7%), popliteal lesion in 2 cases (15.4%), lateral opening greater than 1 cm in 5 cases (38.5%). Though the functional results were similar in both groups, the arthroscopic findings in PCL avulsion fracture were negative in only 2 cases.

CONCLUSION

Arthroscopic examination in PCL avulsion fracture can provide valuable information.

Posterior cruciate ligament and coupled posterolateral instability of the knee

We wanted to investigate the role of the posterior cruciate ligament (PCL) in the knee's posterolateral stability and the magnitude of the coupled posterolateral instability with the knee examined at 90 degrees of flexion. The coupled posterolateral instability of the knee was studied by selective ligament cutting in cadaver knees set at 90 degrees. The coupled posterolateral displacement after cutting the PCL was 173% of the intact knee. With an intact PCL, the coupled posterolateral displacement after cutting the popliteus tendon and lateral collateral ligament with the knee at 90 degrees of flexion was 299% of the intact knee. When the PCL was cut together with the popliteus tendon and lateral collateral ligament, the coupled posterolateral displacement was 367%. The PCL plays an important role in the posterolateral stability of the knee, and its injury may cause mild (< 5 mm) to moderate (5-10 mm) posterolateral instability. Thus, in a knee with posterolateral instability, injury of the PCL must be considered. With an intact PCL, the posterolateral instability was very recognizable with the knee at 90 degrees of flexion, and injury to the PCL further increased the posterolateral instability and caused posterior translation of the knee. Therefore, examination for posterolateral instability of the knee should also be performed with the knee at 90 degrees of flexion, which is much easier to perform in a clinical setting. A positive posterior translation rather than posterolateral instability at different knee positions differentiates knees with combined PCL and posterolateral instability from knees with isolated posterolateral instability.

Tibial plateau fracture with compartment syndrome: a complication of higher incidence in Taiwan

BACKGROUND

Compartment syndrome after tibial plateau fracture has been described, solely as case reports in previously published articles, as a relatively rare complication.

METHODS

A retrospective review of 106 patients with 107 tibial plateau fractures was undertaken from January 1996 to June 1997 at a level I trauma center, and the incidence of compartment syndrome was 10.3%. The diagnosis was based on characteristic clinical symptoms and signs of acute compartment syndrome and/or by measurement of intracompartment pressures. The treatment included fasciotomy of the 4 compartments.

RESULTS

There was a high correlation between the incidence of compartment syndrome and the fracture pattern as well as the mechanism of trauma. Higher-energy traumas (Schatzker's type IV, V, and VI) were associated with a higher incidence of compartment syndrome (30.4% in type VI).

CONCLUSION

The incidence of compartment syndrome after tibial plateau fracture is more common than what has been reported in the literature, especially after high-energy trauma.

Adult monteggia fracture with ipsilateral distal radius fracture: case report

Although the adult Monteggia fracture is a well-known injury, the combination of a Monteggia fracture and an ipsilateral distal radius fracture is extremely rare. It is important for the treating physician to recognize that this injury involves not only the bone elements but also their articulations. The distortion of the integrity of both the elbow and the wrist results in the potential for functional compromise, if inadequately treated. The case report presented here describes a 21-year-old woman with this complex injury resulting from a fall. The injury included a Monteggia type II fracture and an ipsilateral distal radius intra-articular fracture in the left forearm. An excellent result was obtained by surgical intervention in both the radial and ulnar bones. The factors we believe contributed to the excellent result were early diagnosis, anatomic reduction, stable fixation, and early physical exercise. The mechanism of injury giving rise to this rare combination of fractures is discussed, as well as a review of the literature.

Reconstruction of ankle and heel defects by a modified wide-base reverse sural flap

BACKGROUND

Flap reconstruction around the ankle and heel is a technically demanding procedure. Some patients have contraindications for microsurgery, however, limiting the options for local tissue transfer. In this study, we describe our experience with a new flap technique for ankle and heel coverage.

METHODS

We designed a modified wide-base reverse sural flap and applied it to 20 patients with lower leg trauma from 1994 to 1997. All patients sustained Gustilo type IIIb,c open fractures with soft-tissue defects around the ankle and heel. Six cases had chronic osteomyelitis. Most of our patients had contraindications for microsurgery such as old age, poor medical condition, or heavy smoker status. The average age was 69.5 years old, and the average follow-up time was 18.5 months.

RESULTS

All 20 patients underwent successful modified reverse sural flap reconstruction. There were no deep infections, no soft-tissue necrosis, or pressure ulcers. The nonunion rate was 5%. The average time for flap elevation and rotation was 29.3 minutes. No blood transfusion was required. An unsightly scar was the major complaint (60%) from our patients. Seventeen cases (85%) achieved good functional outcomes.

CONCLUSION

This report demonstrates that our design of this modified wide-base reverse sural flap is suitable for flap reconstruction around the ankle and heel; especially for patients who have difficulty in receiving microsurgery. The surgical procedure is simple, and the results are satisfactory.

Knee dislocation: treatment of high-velocity knee dislocation

BACKGROUND

We report the outcomes of patients treated with a new arthroscopic treatment modality for knee dislocation after high-velocity trauma.

METHODS

Twenty-three patients (12 men, 11 women; 25 knees) with traumatic knee dislocation were treated with this technique. Under arthroscopy with gravity inflow irrigation, the ruptured posterior cruciate ligament was reconstructed with a patellar bone-tendon-bone graft, and the anterior cruciate ligament was debrided subacutely. The collateral ligament, meniscus, and capsules were repaired through additional incisions.

RESULTS

The average interval between injury and surgery was 11.1+/-5 days (range, 5 to 25 days). After a mean follow-up period of 27.2+/-7.86 months, the mean extension was 1+/-2 degrees and the average flexion was 129.6+/-4.91 degrees. The mean Lysholm score was 84. There were no major complications.

CONCLUSION

Arthroscopic posterior cruciate ligament reconstruction seems to be an effective treatment for traumatic knee dislocation.

Inferior dislocation of the glenohumeral joint combined with the compartment syndrome of the upper arm: case report

Compartment syndromes occurring in the forearm and leg are not infrequent. However, reports of compartment syndrome of the upper arm are conspicuously rare. Inferior dislocation of the shoulder combined with compartment syndrome has rarely been reported in the literature. We report our experience with a patient with inferior dislocation of the glenohumeral joint combined with compartment syndrome of the upper arm. A 29-year-old man had traumatic inferior dislocation of the glenohumeral joint combined with severe swelling of the shoulder and upper arm. After close reduction, the shoulder and upper arm were still tensely swollen. Compartment pressure of the upper arm was measured using a digital manometer (Quick Pressure Monitor 295-1, Stryker) and remained very high, thus, fasciotomy was performed. After debridement and skin graft, the arm healed without sequelae. When a patient has a fracture dislocation of the shoulder joint associated with a swollen arm, compartment syndrome of the upper arm should be included as a differential diagnosis. Detecting the compartment pressure can confirm the diagnosis of compartment syndrome objectively.

The functional outcome of lower-extremity fractures with vascular injury

Salvage of lower-extremity Gustilo type IIIC fractures is difficult, time-consuming for the patients and physicians, and not universally successful because of poor functional outcomes. Even if successful with limb salvage, the functional result may be unsatisfactory because of mutilating injuries to muscle and nerve, bone loss, and the presence of chronic infection. From July 1991 until July 1994, revascularizations of open IIIC fractures were attempted for wounds with Mangled Extremity Severity Score (MESS) < or = 10. The functional results were evaluated at 2 years after injury. Thirty-six lower-extremity revascularizations were performed on 34 patients, including 1 patient with bilateral distal tibial IIIC fractures and a child with IIIC femoral fracture accompanied by ipsilateral distal tibial amputation. Excluded were patients with below-ankle IIIC fractures as well as patients who underwent immediate amputation at admission. After the revascularization, seven patients with IIIC fractures (7 of 36, 19.4%) underwent secondary amputation within 1 week. At the 2-year follow-up, the overall secondary amputation rate was 25% (9 of 36) and the salvage rate was 75% (27 of 36). Those were no deaths. Of the 29 salvaged limbs among these 27 patients, 23 limbs (23 of 29, 79.3%) required secondary coverage procedures that included 12 free flap transfers (12 of 29, 41.4%). Every patient needed subsequent reconstructive surgery to achieve an acceptable functional result. In this series, MESS was able to predict the secondary amputation rate and the functional result. Sixteen of the 17 limb-salvaged patients with MESS < or = 7 were able to achieve minimal functional requirements, whereas 3 of the 10 patients with MESS = 8 to 10 failed to achieve minimal functional requirements at the 2-year follow-up. Using statistical analysis, we found that the salvaged limbs with MESS < or = 9 exhibited a significant difference in achieving adequate function compared with limbs with MESS > 9. Using our protocol for treatment for IIIC fractures, the threshold for immediate amputation can be raised from MESS = 7 to MESS = 9. Our conclusions are (1) more severely injured limbs have poor functional results, (2) every patient needs subsequent reconstructive surgery, and (3) the MESS may be helpful in decision-making.

Free composite serratus anterior and rib flaps for tibial composite bone and soft-tissue defect

Open fracture in the lower extremity often involves composite bone and soft-tissue defects. For patients with extensive segmental bone defects, vascularized fibular transfers can be utilized and are generally accepted as one of the best options for reconstruction of intercalary defects. In some cases, either bilateral tibias and fibulas are fractured or the contralateral fibula is traumatically damaged or absent, precluding free fibular transfer. If an osteocutaneous fibular flap cannot be used to manage such a defect, a composite serratus anterior and rib flap may be considered. Nine composite serratus anterior and rib flaps, with or without latissimus dorsi transfers, were performed in eight patients between August of 1993 and March of 1994. One patient sustained a left knee disarticulation and underwent reconstruction for a right tibial defect. He failed to achieve lower extremity function within 2 years and was considered a failure. One flap failed, and the patient underwent a below-knee amputation. The remaining six patients received seven composite flaps for tibial and calcaneal defects and could ambulate without assistance. Based on this review, we conclude that the composite serratus anterior and rib flap with optional latissimus dorsi muscle can be used for (1) bilateral tibial fibular fractures, (2) contralateral lower limb amputation with fillet of the amputated leg if the leg is present for harvest, (3) contralateral middle-third fracture of the fibula, (4) patients in whom iliac bone is not suitable because of either a bone defect greater than 10 to 12 cm or previous harvest of bone graft, and (5) extensive composite bone and soft-tissue defects.

Gout with aseptic loosening of cementless total hip arthroplasty--a case report

One case of gouty patient with aseptic loosening of cementless total hip arthroplasty was reported. Mechanical and biological factors may both play some roles in this ollsening hip. From both cup and stem, no direct evidence of loosening was found from pathologic aspect. Further study may need to define relationship between gout and loosening of total hip arthroplasty.