Natural history of popliteal cysts in the pediatric population.

BACKGROUND: Cystic mass lesions in the popliteal area, called popliteal cysts or Baker's cysts, are usually minimally symptomatic and not related to intra-articular morbidity in the pediatric population. Although multiple studies have described cases of spontaneous resolution over a period of several months to a few years, others still consider surgical treatment necessary. Furthermore, no previous studies have used magnetic resonance imaging (MRI) to confirm the disappearance of popliteal cysts. In this retrospective study, we reviewed records of patients with popliteal cysts to investigate the natural history of this disease. METHODS: The medical records of patients with popliteal cysts followed for at least 12 months were retrospectively reviewed. The patient set comprised of 17 knees in 15 males and 3 knees in 2 females. Mean age was 5.6±2.0 years (range, 1.8 to 11.4 y) at their initial visit to the clinic, and mean follow-up period was 53.1±31.6 months (range, 12.6 to 147.8 mo). MRI findings were reviewed for the 16 knees in 13 patients who had undergone MRI. Symptoms and clinical course were extracted from the medical records of all the study subjects and analyzed. RESULTS: Although 6 knees (30%) had histories of pain in the popliteal area, no patient complained of pain at their initial visit. Seventeen cysts (85%) naturally decreased in size or disappeared on clinical examination and/or ultrasound. Cysts confined to either the gastrocnemio-semimembranosus bursa or the subgastrocnemius bursa according to the MRI findings were classified as type I, and cysts which occupied both bursae were classified as type II. Eight knees received MRI examination more than once, and complete disappearance was confirmed in 5 of these knees. All type II cysts converted to type I, and all cysts which completely disappeared were type I before disappearance. CONCLUSIONS: The MRI findings in our study population confirmed that popliteal cysts in pediatric populations can be expected to completely resolve in due course without treatment. LEVEL OF EVIDENCE: Therapeutic study Level IV (Case series).

Intramedullary fixation of proximal phalangeal fractures through a volar extra-tendon sheath approach.

We present an operative technique and the results of intramedullary fixation of proximal phalangeal shaft fractures through a volar extra-tendon sheath approach. A J-shaped nail, which is a curved Kirschner wire sharply bent at the proximal end, was inserted from the palmar aspect of the proximal phalangeal base. Six fingers of the six patients (all male) were treated with this method. The mean age of the patients was 51 years (range, 20-69 years). There were four open and two closed fractures. All fingers attained successful fracture union and one of them had correction loss. No patient complained of pain at the final follow-up, and the average of total active motion was 223° (190° - 255°). This method may be an alternative for treatments of the proximal phalangeal shaft fractures because of its less invasive nature, although it does not offer anatomical reduction.

Effects of autologous platelet-rich plasma on cell viability and collagen synthesis in injured human anterior cruciate ligament.

BACKGROUND: Platelet-rich plasma is a fraction of plasma in which platelets are concentrated. It is reported to represent a source of multiple growth factors that promote tissue repair. In anticipation of the eventual testing of platelet-rich plasma in anterior cruciate ligament (ACL)-deficient patients, we examined the effect of autologous platelet-rich plasma on human ACL cell function in vitro. METHODS: Fresh blood and ACL remnants were obtained from four patients who underwent ACL reconstruction surgery. Platelet-poor plasma and platelet-rich plasma were prepared from the blood samples. The concentrations of various growth factors in each preparation were tested with use of enzyme-linked immunosorbent assays. Isolated ACL cells were cultured in the presence of 5% fetal bovine serum, 5% platelet-poor clot releasate, 5% platelet-rich clot releasate, or 10% platelet-rich clot releasate. Platelet-rich plasma and platelet-poor plasma releasates were applied to the ACL cells from the same patient autologously. Cell viability and collagen synthesis in each group were analyzed, and semiquantitative gene-expression assays for type-I and III collagen were also performed. RESULTS: The concentrations of the main growth factors (transforming growth factor-beta, platelet-derived growth factor, epidermal growth factor, and vascular endothelial growth factor) were much higher in platelet-rich clot releasate than in platelet-poor clot releasate. In vitro treatment of ACL cells with platelet-rich clot releasate resulted in a significant increase in cell number compared with platelet-poor clot releasate. Total collagen production by the platelet-rich clot releasate-treated cells was significantly higher than that of the platelet-poor clot releasate-treated cells only because of enhanced cell proliferation. There was no significant effect of platelet-rich clot releasate treatment on gene expression for type-I collagen, but expression of type-III collagen was significantly enhanced by the treatment with platelet-rich clot releasate. CONCLUSIONS: These results suggest that autologous platelet-rich plasma can enhance ACL cell viability and function in vitro.

Trans-web approach for fixation of avulsion fractures of the proximal phalangeal base: report of two cases.

Although displaced fractures of the lateral aspect of the base of the proximal phalanx can be treated surgically, previously described approaches to the fracture are not necessarily easily performed. We describe a trans-web approach to the metacarpophalangeal joint and report 2 clinical cases. This technique allows the fracture fragments to be reduced and fixed with minimal risk of damage to the adjacent structures.

Objective assessments of medial osteoarthritic knee severity by MRI: new computer software to evaluate femoral condyle contours.

An irregular contour of the medial femoral condyle (MFC) on magnetic resonance imaging (MRI) appears to indicate the severity of medial-type knee osteoarthritis (OA). The purpose of this study was to establish a system to enable objective assessments of OA knee severity using newly developed software that semi-automatically measures irregularity of the MFC. (1) We evaluated 48 patients aged 50-83 years with 55 knees of medial-type OA. The following scores were recorded: Lysholm score, visual analogue scale (VAS) and the Japanese Knee Osteoarthritis Measure (JKOM). MFC irregularity was automatically calculated by newly programmed computer software. Four parameters for condyle irregularity were calculated: (a) the average thickness of the contour (ATC), (b) the ratio of the upper surface length to the lower surface length of the contour (RUL), (c) average squared thickness of the contour (ASTC) and (d) standard deviation of the contour thickness (SDC). (2) Nine knees that underwent total knee arthroplasty were further analysed histopathologically and compared with irregularity score. Statistically, the RUL and SDC were significantly correlated with the Lysholm score, VAS and JKOM, with good reliability. Histological examinations showed that an irregular contour reflected the density of cystic lesions formed in subchondral bone. An irregularity of MFC on MRI is correlated with OA disease severity clinically and histopathologically. The new computer software is useful to objectively assess OA disease severity.

Detection of pain-related molecules in the subchondral bone of osteoarthritic knees.

Knee pain is predominant among osteoarthritis (OA) patients, but the mechanism is poorly understood. We investigated subchondral bone as a source of OA knee pain using immunohistochemistry. Fifteen medial-type OA knees with minimum involvement of the lateral compartment determined by X-ray as well as magnetic resonance imaging that received total knee arthroplasty (TKA) were involved. Each pair of the medial femoral condyle (MFC) and lateral femoral condyle (LFC) was compared obtained at the time of TKA. Osteocartilaginous MFC and LFC specimens were histologically examined and stained with antibodies against cyclooxygenase 1 (Cox-1), cyclooxygenase 2 (Cox-2), substance P, tumor necrosis factor-alpha (TNF-alpha), and neuron-specific class III beta-tubulin (TUJ1), a pan-neuronal marker. Formation of cystic lesions was more frequently seen in the MFC. The lesions were composed of vascular endothelial cells, osteoclasts, and mononuclear cells and were present in similar proportions between the MFC and the LFC. Four out of 15 MFC specimens were positive for Cox-1, 15 for Cox-2, and 13 for TNF-alpha. No LFC specimens were positive for any antibodies. Substance P-positive and TUJ1-positive fibers were found in the subchondral area of the MFC, but not in the LFC. Pathological changes in the subchondral bone can be a source of knee pain, which was detectable by the positive immunoreactivity of substance P, Cox-2, TNF-alpha, and TUJ1, in the subchondral bone of affected compartments. The relatively immediate reduction in pain obtained by TKA might account for the involvement of the subchondral bone in knee pain because most of the affected subchondral plate is excised in TKA (debridement effect of TKA).

Chronic recurrent dislocation of the distal interphalangeal joint of the finger: case report.

We present a case of chronic, recurrent dislocation of the distal interphalangeal joint of the little finger after traumatic dislocation. Intraoperative findings showed complete avulsion of the volar plate from the base of the distal phalanx and laxity of the ulnar collateral ligament. The volar plate was reattached by the suture anchor technique and reinforced by the ulnar half of the flexor digitorum profundus tendon.

The pattern of distribution of PGP 9.5 and TNF-alpha immunoreactive sensory nerve fibers in the labrum and synovium of the human hip joint.

To date, there has been no report clarifying the existence of sensory nerve fibers as the origin of the hip joint pain of osteoarthritis. We examined the existence of sensory nerve fibers in osteoarthritis (OA), osteonecrosis of the femoral head (ONFH), and femoral neck fracture of the human hip joint. Ten labra of 10 human hip joints were harvested during a total hip arthroplasty. Each labrum was separated into 12 sections and we used three sections for analysis, which included 2 weight-bearing and 1 non-weight-bearing portion. Protein gene product 9.5 (PGP 9.5) immunoreactive sensory nerve fibers were found in the labrum and synovium harvested from the weight-bearing portion in the OA group. Some of these sensory nerve fibers were also positive for tumour necrosis factor alpha (TNF). The PGP 9.5 immunoreactive sensory nerve fibers existed in the labrum tissue and inflammatory TNF positive cells were observed in the hyperplastic synovium. On the other hand, we could not demonstrate PGP 9.5 or TNF immunoreactive sensory nerve fibers and cells in any of the ONFH group or the non-weight-bearing portion in the OA group. These data suggest that the pain of ONFH and OA of the hip joint have different pathogenetic mechanisms and that the invasion of sensory nerve fibers containing TNF may be involved in the pathogenesis of pain in the human hip joint affected by OA.

Evaluation of joint laxity against distal traction force upon flexion in cruciate-retaining and posterior-stabilized total knee arthroplasty.

BACKGROUND: Several studies have reported varus-valgus stability in the extension position after total knee arthroplasty (TKA). However, few studies have evaluated joint laxity in the flexion position postoperatively. The purpose of the study was to evaluate joint laxity against distal traction force on flexion after cruciate-retaining and posterior-stabilized total knee arthroplasties. METHODS: A total of 44 knees (22 knees cruciate-retaining, 22 knees posterior-stabilized) in 40 patients with osteoarthritis were tested in this study. The subjects were seated at a table and their knee joints were fixed at 80 degrees of flexion to avoid overlapping images of condyles and the femoral shaft. Tibial shafts were adjusted to be parallel to the radiographic films, and posteroanterior radiographs were obtained. Flexion stress tests were performed with a distal traction of 100 N at a neutral foot position. Radiographs were obtained at neutral and traction positions. The distance from the perpendicular line of the top of the polyethylene insert to the midpoint on the tangential line of the femoral condyle was measured (joint space distance) at each side. RESULTS: In the flexion-neutral position, average joint space distances were 0.1 +/- 0.2 mm in cruciate-retaining (CR) TKA knees and 0.2 +/- 0.3 mm in posterior-stabilized (PS) TKA knees. With flexion-traction stress tests, the average joint space distances were 0.5 +/- 0. 5 mm in CR TKA knees 2.4 +/- 1.2 mm in PS TKA knees. Average changes of joint space distances between the two positions were 0.3 +/- 0.4 mm (CR TKA) and 2.2 +/- 1.5 mm (PS TKA). The changes in joint space distances between neutral and traction positions of PS TKA knees were significantly larger than those of CR TKA knees in flexion stress tests (P < 0.01). CONCLUSION: The posterior cruciate ligament acted as a stabilizer against distal traction force in the CR-TKA knees. However, the laxity of PS-TKA knees against distal force differed among individual cases.

RGD peptide-induced cell death of chondrocytes and synovial cells.

BACKGROUND: Small peptides including the Arg-Gly-Asp (RGD) motif have been used in studies on cell-extracellular matrix (ECM) attachment due to their ability to disturb integrin-mediated attachment on the cell surface. As another biological action of RGD peptides, several reports have shown that RGD peptides are incorporated into cytoplasm and induce apoptosis by direct activation of caspase-3. This study evaluated the effect of RGD peptides on chondrocytes and synovial cells and studied the involvement of caspases. METHODS: Chondrocytes and synovial cells were isolated and cultured from the knee joints of New Zealand White rabbits. Cells were incubated in serum-free medium with peptides (RGD, RGDS, GRGDSP, GRGDNP, RGES), and the survival rates were evaluated. The rate of apoptotic cells was measured by flow cytometry in cells treated with RGDS, GRGDSP, and RGES. Caspase-3, -8 and -9 activity was measured in cells treated with RGDS and GRGDSP. Osteochondral explants harvested from rabbits were also incubated with RGD peptides (RGDS, GRGDSP, and GRGDNP), and the survival rate of chondrocytes was evaluated. RESULTS: The survival rate of cultured chondrocytes was significantly decreased in the GRGDSP- and GRGDNP-treated groups. The survival rate of synovial cells was significantly decreased with four of the RGD peptides (RGD, RGDS, GRGDSP, and GRGDNP) at 5 mM, and in the RGDS- and GRGDSP-treated groups at 1 mM. Flow cytometric assay revealed increases of apoptotic chondrocytes with GRGDSP and increases of apoptotic synovial cells with RGDS and GRGDSP. Caspase-3 was activated in chondrocytes treated with GRGDSP and it was also activated in synovial cells treated with RGDS and GRGDSP. Caspases-8 and -9 were not activated in chondrocytes or in synovial cells. The survival rate of chondrocytes in explants decreased in the superficial layer with all three RGD peptides (RGDS, GRGDSP, and GRGDNP) and in the middle layer with GRGDSP. CONCLUSIONS: RGD peptides induced apoptosis in cultured chondrocytes as well as in cells in cartilage explants and synovial cells, presumably through direct activation of caspase-3.

Spontaneous recurrent hemarthrosis of the knee in the elderly: arthroscopic treatment and etiology.

PURPOSE: To elucidate the etiology of and find a preferable surgical treatment for spontaneous recurrent hemarthrosis in osteoarthritic knee joints arthroscopically. METHODS: Nineteen patients referred to our institution from affiliate hospitals between April 1998 and October 2006 were involved in this study. Their demographics, preoperative radiographic findings, preoperative magnetic resonance imaging (MRI) findings, arthroscopic findings and procedures performed, the patient's medical history, and the postoperative clinical course were retrospectively reviewed. RESULTS: There were 9 male and 10 female patients with average age of 61.9 years (range, 41 to 83 yrs). The average number of joint aspirations before surgery was 5.4. The average time from onset to arthroscopy was 10 months. Radiographs showed 2 knees with isolated lateral compartment osteoarthritis (OA), one with isolated patellofemoral (PF) OA, 14 with medial and lateral compartment OA, and 2 with tricompartmental OA. Classifying them according to the dominant compartment, 6 knees were medial-dominant OA, 11 lateral-dominant OA, and 2 PF-dominant OA. The MRI scans revealed 18 grade III lateral menisci and 1 grade II lateral menisci. Even with 6 medial-dominant OAs, lateral meniscal involvement was more obvious than medial meniscal involvement on MRI. Subtotal lateral meniscectomy accompanied with coagulation of the bleeding points was performed on 17 cases. For 2 PF OA cases, synovectomy and a histologic examination of synovium were performed. Remission was obtained for 18 cases. The unsuccessful case had cirrhosis of the liver. CONCLUSIONS: A majority of the patients (17 of 19) had degenerative torn lateral menisci confirmed with MRI and at arthroscopy. Successful outcomes were achieved by meniscectomy and coagulation. Most so-called spontaneous recurrent hemarthroses in OA knee joints appear to be attributable to torn lateral menisci. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Radial head dislocation with ulnar plastic deformation in children: an osteotomy within the middle third of the ulna.

This retrospective study includes 6 patients (average age, 8.7 years) with a dislocation of the radial head and ulnar plastic deformation. All were Monteggia fractures, Bado type I equivalents. The maximum ulnar bow was near the midulna. Five patients underwent an ulnar osteotomy, with elongation and reduction of the angulation within the middle third of the ulna, and open reduction of the radial head. One patient underwent an ulnar osteotomy with only elongation. The osteotomy sites were stabilized by a plate and screws or Kirschner wires. Mean follow-up was 3.4 years. Postoperatively, the average elbow range of motion was extension to 0 degrees, flexion to 138 degrees, forearm supination to 90 degrees, and forearm pronation to 88 degrees. Results in all patients were rated as excellent. One nonunion occurred. An osteotomy performed within the middle third of the ulna, combined with open reduction of the radial head, resulted in excellent clinical outcomes.

In vivo maturation of scaffold-free engineered articular cartilage on hydroxyapatite.

Tissue engineering is a promising approach, not only for cartilage, but also for osteochondral repair. Recent studies have demonstrated that scaffold-free cartilaginous tissue can be engineered using the alginate-recovered-chondrocyte (ARC) method. This method has also been applied to form osteochondral tissue using bovine articular chondrocytes and coralline hydroxyapatite (HA). The purpose of this study was to test whether osteochondral tissue, fabricated in vitro using the ARC method combined with a block of HA, would undergo maturation in vivo using a subcutaneous model in immunodeficient mice. Articular chondrocytes were isolated from the cartilage of New Zealand white rabbits and cultured in alginate beads. The cells with their associated matrix were recovered by dissolving the alginate beads with a sodium citrate buffer, resuspended in media and seeded onto a porous HA block. After 4 weeks of culture, some samples were analyzed, and others were implanted into subcutaneous pockets in nude mice. The analysis involved removing the cartilage portion of the de novo-formed ARC-HA graft and performing biochemical and histological examinations. Some samples were subjected to nondecalcified histology. Histological and immunohistochemical analyses of cartilaginous tissue were performed at 0, 2, 4, and 8 weeks after implantation. Biochemical characteristics were examined at 0, 4, and 8 weeks. The size and shape of the implanted ARC osteochondral tissue changed with time. The histological and immunohistochemical examination of the tissue revealed that it contained a cartilage-like matrix that stained strongly with Toluidine blue and for collagen type II. The proteoglycan (PG) content had increased significantly at 4 weeks from baseline. However, by 8 weeks, the PG content had decreased from 4 weeks. The results presented here represent a possible approach to form a tissue-engineered osteochondral implant. Further studies are needed to improve biomechanical properties of the osteochondral implant to be suitable for surgical transplantation.

Closed intramedullary fixation for metacarpal fractures using J-shaped nail.

The purpose of this study is to present the results of a new intramedullary fixation technique for metacarpal fractures. A J-shaped nail, which is a curved 2.0 mm diameter Kirschner wire sharply bent at the proximal end, was inserted from the dorsal aspect of the metacarpal base. Twenty-one metacarpal fractures (five transverse shaft fractures and 16 neck fractures) in 19 hands of 18 patients with were operated by this technique. All fractures had successful unions. Clinical and radiographic results were excellent in all ten hands that had excluded concomitant injuries. There was no mechanical irritation of the skin or extensor tendons in any patient. This intramedullary fixation technique is very useful for neck or transverse shaft fractures of the metacarpals without concomitant injuries such as severe soft tissue damage.

Granulocyte colony-stimulating factor attenuates neuronal death and promotes functional recovery after spinal cord injury in mice.

Granulocyte colony-stimulating factor (G-CSF) is a protein that stimulates differentiation, proliferation, and survival of granulocytic lineage cells. Recently, a neuroprotective effect of G-CSF was reported in a model of cerebral infarction. The aim of the present study was to elucidate the potential therapeutic effect of G-CSF for spinal cord injury (SCI) in mice. We found that G-CSF is neuroprotective against glutamate-induced cell death of cerebellar granule neurons in vitro. Moreover, we used a mouse model of compressive SCI to examine the neuroprotective potential of G-CSF in vivo. Histologic assessment with cresyl violet staining revealed that the number of surviving neurons in the injured spinal cord was significantly increased in G-CSF-treated mice. Immunohistochemistry for neuronal apoptosis revealed that G-CSF suppressed neuronal apoptosis after SCI. Moreover, administration of G-CSF promoted hindlimb functional recovery. Examination of signaling pathways downstream of the G-CSF receptor suggests that G-CSF might promote functional recovery by inhibiting neuronal apoptosis after SCI. G-CSF is currently used in the clinic for hematopoietic stimulation, and its ongoing clinical trial for brain infarction makes it an appealing molecule that could be rapidly placed into trials for patients with acute SCI.

Adenovirus vector-mediated ex vivo gene transfer of brain-derived neurotrophic factor to bone marrow stromal cells promotes axonal regeneration after transplantation in completely transected adult rat spinal cord.

The aim of this study was to evaluate the efficacy in adult rat completely transected spinal cord of adenovirus vector-mediated brain-derived neurotrophic factor (BDNF) ex vivo gene transfer to bone marrow stromal cells (BMSC). BMSC were infected with adenovirus vectors carrying beta-galactosidase (AxCALacZ) or BDNF (AxCABDNF) genes. The T8 segment of spinal cord was removed and replaced by graft containing Matrigel alone (MG group) or Matrigel and BMSC infected by AxCALacZ (BMSC-LacZ group) or AxCABDNF (BMSC-BDNF group). Axons in the graft were evaluated by immunohistochemistry and functional recovery was assessed with BBB locomotor scale. In the BMSC-BDNF group, the number of fibers positive for growth associated protein-43, tyrosine hydroxylase, and calcitonin gene-related peptide was significantly larger than numbers found for the MG and BMSC-LacZ groups. Rats from BMSC-BDNF and BMSC-LacZ groups showed significant recovery of hind limb function compared with MG rats; however, there was no significant difference between groups in degree of functional recovery. These findings demonstrate that adenovirus vector-mediated ex vivo gene transfer of BDNF enhances the capacity of BMSC to promote axonal regeneration in this completely transected spinal cord model; however, BDNF failed to enhance hind limb functional recovery. Further investigation is needed to establish an optimal combination of cell therapy and neurotrophin gene transfer for cases of spinal cord injury.

Rho kinase inhibitor improves motor dysfunction and hypoalgesia in a rat model of lumbar spinal canal stenosis.

STUDY DESIGN: Immunohistochemical and behavioral study using a rat cauda equina compression model. OBJECTIVE: To investigate, after cauda equina compression by spinal canal stenosis (SCS), Rho activation in the spinal cord and cauda equina, and the effect of intrathecal administration of a Rho kinase inhibitor on hypoalgesia and motor dysfunction. SUMMARY OF BACKGROUND DATA: Compression of the cauda equina caused by SCS is a common clinical disorder associated with sensory disturbance and intermittent claudication. Cauda equina compression is thought to reduce blood flow and result in nerve degeneration caused by various cytokines. Rho, a member of the small GTPases, is a signal transmitter. It promotes Wallerian degeneration, decreases blood flow in the spinal cord and brain, and increases expression of several cytokines. Currently, Rho kinase inhibitor is used clinically to treat progressive nerve damage due to cerebrovascular disorders. However, its effect for SCS has not been evaluated. METHODS: Forty-two 6-week-old male Sprague-Dawley rats (200-250 g) were used. For the SCS model (n = 27), a small piece of silicon was placed under the lamina of the fourth lumbar vertebra. In the sham-operated group, laminectomies were performed at L5 only (n = 15). We examined mechanical sensitivity and motor function using von Frey hairs and a treadmill, and immunohistochemically localized Rho in the spinal ventral neurons, axons, and Schwann cells in the cauda equina. We also examined the effects of intrathecally administered Rho kinase inhibitor for hypoalgesia or motor dysfunction caused by SCS. RESULTS: We observed motor dysfunction and hypoalgesia and activated Rho-immunoreactive cells in spinal ventral neuroreported to induce neurite and axonal outgrowth in the spinal cord and brain after nervous system injury. In addition, 1 report showed that Rho kinase was involved in Wallerian degeneration that was rescued by Rho kinase inhibitor. Furthermore, it is thought that Rho is involved in TNF-alpha and interleukin (IL) production in the central nervous system, and the production was inhibited by administering Rho kinase inhibitor in the central nervous system. Regardns, axons, and Schwann cells in the cauda equina. Intrathecal administration of Rho kinase inhibitor improved mechanical hypoalgesia and motor dysfunction caused by SCS. CONCLUSION: Activated Rho may play an important role in nerve damage in the cauda equina in SCS. Rho kinase inhibitor may be a useful tool in determining the pathomechanism of cauda equina syndrome caused by SCS.

Humeral shortening and inferior subluxation as sequelae of septic arthritis of the shoulder in neonates and infants.

BACKGROUND: Although humeral shortening as a sequel of septic arthritis of the shoulder in infants has been reported in previous studies, functional disorders of the shoulder resulting from humeral shortening have not yet been clarified. In this study, we retrospectively investigated the long-term outcome of septic arthritis of the shoulder in neonates and infants and examined the relationship between growth disturbance of the humerus and decreased range of motion with respect to glenohumeral joint laxity. METHODS: We reviewed the cases of fifteen patients (sixteen shoulders) with an age of a few days to 2.6 years at the onset of the disease who were followed from 5.0 to 17.9 years. We noted the initial treatment method and evaluated humeral length and shoulder function at the time of the final follow-up. For the final treatment results, we classified the shoulders with normal findings on radiographs as Grade I, those with humeral head deformity as Grade II, and those with humeral head deformity with inferior subluxation as Grade III. RESULTS: Primary treatment included arthrotomy in ten shoulders. The delay between the onset of the disease and surgery ranged from three to twenty-six days. At the time of the final follow-up, the results were Grade I in five shoulders, Grade II in six shoulders, and Grade III in five shoulders. The mean humeral shortening was 0.1 cm for Grade-I shoulders, 0.9 cm for Grade-II shoulders, and 7.3 cm for Grade-III shoulders. All Grade-III shoulders had >or=3 cm of shortening, and four of the five Grade-III shoulders showed limitation of elevation (abduction of <130 degrees ). None of the Grade-III shoulders had undergone arthrotomy within ten days after the onset of the disease. CONCLUSIONS: Inferior subluxation of the humeral head related to shoulder dysfunction resulting from early childhood septic arthritis accompanied humeral shortening of >or=3 cm and was only observed in patients who did not undergo arthrotomy of the shoulder within ten days after the onset of the infection.

Nerve regeneration after radiofrequency application.

BACKGROUND: Many patients with chronic tendinosis have experienced early pain relief after application of bipolar radiofrequency treatment. It is hypothesized that the mechanism of action may be the acute degeneration and/or ablation of sensory nerve fibers. HYPOTHESIS: After ablation or degeneration by bipolar radiofrequency, nerve fibers will have the ability to regenerate with time. STUDY DESIGN: Controlled laboratory study. METHODS: Eighteen Sprague-Dawley rats were used in this study. These rats were divided into 3 groups (30, 60, and 90 days after bipolar radiofrequency). These rats were treated with 2 points of bipolar radiofrequency applications to the left hindpaws with the Topaz microdebrider device. Right hindpaws were used as the contralateral control. Tissues were processed for neural class III beta-tubulin or calcitonin gene-related peptide immunohistochemistry by using the free-floating avidin biotin complex technique. The numbers of neural class III beta-tubulin-immunoreactive and calcitonin gene-related peptide-immunoreactive nerve fibers in the epidermis were counted and compared with those in the contralateral control. RESULTS: Although the numbers of nerve fibers demonstrated by both the antibodies of neural class III beta-tubulin and calcitonin gene-related peptide were significantly decreased (P <.0001) until 60 days after bipolar radiofrequency treatment, regeneration of the epidermal nerve fibers occurred 90 days after treatment. CONCLUSION: Bipolar radiofrequency treatment induced degeneration of sensory nerve fibers immediately after treatment, but by 90 days posttreatment, there was evidence of complete regeneration. CLINICAL RELEVANCE: Early degeneration followed by later regeneration of nerve fibers after bipolar radiofrequency treatment may explain long-term postoperative pain relief after microtenotomy for tendinosis.

Effects of a single percutaneous injection of basic fibroblast growth factor on the healing of a closed femoral shaft fracture in the rat.

Recently, bioactive agents to stimulate bone formation have been available in the orthopedic field. We have shown previously that a single, local injection of basic fibroblast growth factor (bFGF) contributes to the formation of a larger cartilage (soft callus) but does not promote replacement of the cartilage by osseous tissue during experimental closed femoral fracture healing. Aiming at a clinical application, the present study was undertaken to clarify the effects of locally injected bFGF on bone (hard callus) formation and the mechanical properties of the callus in closed fracture healing in rats. Immediately after fracture, a carrier (200 muL of fibrin gel) containing 100 mug of bFGF or carrier alone was applied to the fracture site. At days 42 and 56 postfracture, the bone union rate, bone mineral density (BMD), and mechanical properties (strength and stiffness) of the callus were evaluated. Unexpectedly, with the exception of reduced stiffness in the FGF-injected callus at day 56, none of these parameters showed a significant difference between the control and the FGF-injected groups. Furthermore, the temporal expression pattern of OPN mRNA during healing was very similar between groups. We conclude that, in the healing of closed fractures of long bones, administration of bFGF forms a larger callus but does not necessarily accelerate the healing process.