Naohito Hibino

Vertebral rounding deformity in pediatric spondylolisthesis occurs due to deficient of endochondral ossification of the growth plate: radiological, histological and immunohistochemical analysis of a rat spondylolisthesis model.

Study Design. A study using rat spondylolisthesis models. Objective. To clarify pathomechanism of vertebral rounding deformity in pediatric spondylolisthesis. Summary of Background Data. For high-grade slippage, rounding of sacrum surface associated with L5 spondylolisthesis is reported to be the most responsible risk factor. However, the exact pathomechanism of the rounding deformity is yet to be clarified. Methods. Spondylolisthesis rat model (4-week-old) was used. Radiographs were taken weekly for 5 weeks after the surgery. The lumbar spines were harvested for histology. Hematoxylin and eosin, alcian blue staining, and tartrate-resistant acid phosphatase staining were used. Immunohistochemically, the growth plate cartilage was studied for type II and X collagen. A modified bone histomorphometric analysis was also performed. Results. Radiographs showed slippage 1 week after surgery. Rounding deformity was obvious 2 weeks after surgery. The rounding deformity progressed with time. Three weeks after surgery, the specific columns of growth plate were unclear at the anterior corner, which corresponded to the rounding surface observed on radiographs. Instead, a huge mass of cartilage was observed at that site. Tartrate-resistant acid phosphatase-positive cells were observed in the vicinity of the growth plate except in relation with the anterior corner. The growth plate and cartilage mass at the anterior corner stained positive for type II collagen. Chondrocytes in the hypertrophied layer stained positively for type X collagen; however, staining was faint at the anterior corner. The results suggested that the chondrocytes at the anterior did not form, morphologically and functionally, the normal growth plate. From histomorphometrical analysis, the normal posterior growth plate made endochondral bonegrowth in 510 ± 20 &mgr;m for a week, whereas the anterior corner in 200 ± 15 &mgr;m. Conclusion. Deficient endochondral ossification of the growth plate in the anterior upper corner of the vertebra could be the pathomechanism of the rounding deformity of the sacrum.

Callus formation during healing of the repaired tendon-bone junction

This study was undertaken to elucidate the mechanism of biological repair at the tendon-bone junction in a rat model. The stump of the toe flexor tendon was sutured to a drilled hole in the tibia (tendon suture group, n = 23) to investigate healing of the tendon-bone junction both radiologically and histologically. Radiological and histological findings were compared with those observed in a sham control group where the bone alone was drilled (n = 19). The biomechanical strength of the repaired junction was confirmed by pull-out testing six weeks after surgery in four rats in the tendon suture group. Callus formation was observed at the site of repair in the tendon suture group, whereas in the sham group callus formation was minimal. During the pull-out test, the repaired tendon-bone junction did not fail because the musculotendinous junction always disrupted first. In order to understand the factors that influenced callus formation at the site of repair, four further groups were evaluated. The nature of the sutured tendon itself was investigated by analysing healing of a tendon stump after necrosis had been induced with liquid nitrogen in 16 cases. A proximal suture group (n = 16) and a partial tenotomy group (n = 16) were prepared to investigate the effects of biomechanical loading on the site of repair. Finally, a group where the periosteum had been excised at the site of repair (n = 16) was examined to study the role of the periosteum. These four groups showed less callus formation radiologically and histologically than did the tendon suture group. In conclusion, the sutured tendon-bone junction healed and achieved mechanical strength at six weeks after suturing, showing good local callus formation. The viability of the tendon stump, mechanical loading and intact periosteum were all found to be important factors for better callus formation at a repaired tendon-bone junction.

Expanding the utility of modified vascularized femoral periosteal bone-flaps: An analysis of its form and a comparison with a conventional-bone-graft

BACKGROUND Vascularized medial femoral condyle (MFC) corticoperiosteal bone-flap is a well-accepted technique when dealing with tissue defects or infection. Its role in refractory conditions and in the possible use for options concerning modifications of this bone-flap compared to a conventional iliac bone graft (conventional-graft) are rarely discussed. METHODS We reviewed 21 consecutive cases concerning alternatives with some modifications of original MFC bone-flap surgery used to treat refractory conditions with bone defects, necrosis, or infection in the extremities. We present our devised approaches for this boneflap, and especially modifications of the grafted bone (including strut bone, perforator to the vastus medialis muscle, and the use of one vascular pedicle for some bone flaps) as well as the combined use of artificial bone as hybrid bone transplantation. We also compared the clinical results of 21 cases that received a conventional-graft. RESULTS AND CONCLUSIONS Following flap placement, 100% of the nonunion sites healed in an average of 2 months, which was significantly shorter than 5.5 months for the conventional-graft. The results showed the expanding possibility for options with regard to the form and options of this bone-flap as well as the shortening the duration of treatment, especially at the site of an infected distal tibia, insertion of the Achilles tendon on the posterior aspect of calcaneal osteomyelitis, distal end of the clavicle, clavicle or forearm with a bone defect, small bones with refractory conditions, and a femur without implant failure. However, it was not efficient for treating a forearm without bone defect.

Staged External Fixation for Chronic Fracture-Dislocation of the Proximal Interphalangeal Joint: Outcomes of Patients With a Minimum 2-Year Follow-Up

PURPOSE To introduce a new surgical strategy for chronic fracture-dislocations of the proximal interphalangeal (PIP) joint with 2-staged external fixation. We also assessed the results of this method in all of our patients with at least 2 years of follow-up. METHODS We used the procedure in 6 cases. For the first step, we applied mini external fixators for 1 week before surgery to apply traction to the PIP joint with sufficient force to stretch the dislocated joint components. The second procedure was surgical release of the PIP joint and an attempt at percutaneous reduction and fixation. This was not possible in 4 cases, and we performed an open reduction and corrective osteotomy. Postoperative early rehabilitation was achieved under controlled movement using an external fixator that allowed PIP joint flexion and extension. RESULTS At long-term follow-up (mean, 3.5 y), the range of movement of PIP joints had increased by 76°, and that of distal interphalangeal joints by 35°. Osteochondral remodeling likely occurred not only while the joint was protected with the dynamic external fixator during a 12-week period (range, 8-14 wk), but also after removal. CONCLUSIONS Preoperative traction softens the PIP joint, facilitating both surgery and rehabilitation. Postoperative early exercise with controlled movement, while maintaining concentric reduction with the external fixator, may accelerate osteochondral repair of the injured PIP joint.

Open dislocation of the proximal interphalangeal joint of the little finger subsequent to chronic radial collateral ligament injury: a case report of primary ligament reconstruction with a half-slip of the flexor digitorum superficialis: Case Report

Open dislocation of the proximal interphalangeal (PIP) joint is relatively rare. We report a case of a 32-year-old man who had open dislocation of the PIP joint of the little finger while playing American football. He had a history of chronic radial collateral ligament injury. We reconstructed the radial collateral ligament with a half-slip of the flexor digitorum superficialis tendon.

Collateral ligament repair augmented by an A2 pulley flap for chronic ligament rupture of the finger metacarpophalangeal joint

Symptomatic chronic collateral ligament rupture of finger metacarpophalangeal (MP) joints is not common. If conservative treatments are not effective, it may require reconstruction due to shrinkage of the ligament. Tendon grafting using palmaris longus tendon grafting can be used (Oka et al., 2003). A part of the A2 pulley can be used to augment the repair of the chronic collateral ligament rupture. Here we describe a case treated with this method. A 51-year-old woman injured the MP joint of her ring finger by forced ulnar deviation while driving. She experienced severe radial-sided pain in the MP joint after the injury and consulted a local doctor. Although no abnormal findings were evident on radiographs, she continued to experience pain during forward ulnar stress on the MP joint. We saw her 6 months after the injury. There was radial-sided MP joint tenderness. There was no excessive laxity or instability on stress testing. Her symptoms did not resolve with non-operative treatment. Via a dorsal approach we found a shrunken radial collateral ligament, such that direct repair was not possible without a gap (Figure 1(a)). Next a volar approach was performed (Figure 1(a)), the proximal portion of the A2 pulley was exposed and raised as a flap and used to augment the ligament reconstruction Letters to the Editor Short Report Letters 593472 JHS0010.1177/1753193415593472Journal of Hand Surgery (European Volume)Short report letters research-article2015

Surgical Strategy and Techniques for Low-Profile Dorsal Plating in Treating Dorsally Displaced Unstable Distal Radius Fractures

Background The low‐profile dorsal locking plating (DLP) technique is useful for treating dorsally comminuted intra‐articular distal radius fractures; however, due to the complications associated with DLP, the technique is not widely used. Methods A retrospective review of 24 consecutive cases treated with DLP were done. Results All cases were classified into two types by surgical strategy according to the fracture pattern. In type 1, there is a volar fracture line distal to the watershed line in the dorsally displaced fragment, and this type is treated by H‐framed DLP. In type 2, the displaced dorsal die‐punch fragment is associated with a minimally displaced styloid shearing fracture or a transverse volar fracture line. We found that the die‐punch fragment was reduced by the buttress effect of small L‐shaped DLP after stabilization of the styloid shearing for the volar segment by cannulated screws from radial styloid processes. At 6 months after surgery, outcomes were good or excellent based on the modified Mayo wrist scores with no serious complications except one case. The mean range of motion of each type was as follows: the palmar flexion was 50, 65 degrees, dorsiflexion was 70, 75 degrees, supination was 85, 85 degrees, and pronation was 80, 80 degrees; in type 1 and 2, respectively. Conclusion DLP is a useful technique for the treatment of selected cases of dorsally displaced, comminuted intra‐articular fractures of the distal radius with careful soft tissue coverage.

Salmonella osteomyelitis of the distal radius in a healthy young adult patient: Report of a rare case and literature review

Salmonella osteomyelitis of the radius in a healthy individual is very rare. We present such a case involving the distal radius of a healthy 23-year-old man without underlying disease or possible episode. He had right wrist pain for approximately 3 years, and osteolytic lesion was seen in the right distal radius. He underwent surgical treatment, and salmonella was isolated from pus in the lesion. Postoperative antibiotics successfully treated his infection. He had no sign of recurrence, but the point of entry for infection remains unknown.

Surgical rehabilitation for correction of severe flexion contracture of the proximal interphalangeal joint by modified Ilizarov method

(p<0.001). WBC values were also higher in mimickers, albeit not significantly. No statistically significant differences were found for the other inflammatory markers between infected patients and mimickers (Table 1). Sixty-one infected patients (46%) showed mild elevation of CRP (>6 to <40 mg/L), 21 (16%) showed moderate elevation (>40 to <100 mg/L) and nine (7%) showed marked elevation (>100 mg/L). Patients with infection-mimicking diseases showed mild elevation of CRP in nine cases (33%), moderate elevation in nine (33%) cases and marked elevation in nine (33%) cases. An elevated CRP was observed in 30 (48%) infections in Zone 1 (distal) and in 61 (87%) in the zone proximal to the digits. Schmidt-Matthiesen and Oremek (1990) reported CRP sensitivity levels of 0.6–0.9 and specificity levels of 0.8–0.9 in the diagnosis of hand infections. In our study, the sensitivity of CRP was 0.69. The sensitivity of all other inflammation markers was 0.5 or lower. PCT appears to be of no diagnostic value in hand infections. The specificity of all inflammation markers was inadequate for diagnosis. All mimickers showed elevated CRP values; 66% had moderately or markedly elevated CRP values, which resulted in a specificity of zero for CRP in our study. Only 62% of patients with infections showed mildly or moderately elevated CRP values. Six out of nine infected patients with markedly elevated CRP values had additional foci of infection or lymphangitis. This may explain the high CRP values. In our study, just below 50% of patients with finger infections (zone 1) had elevated CRP values. However, physiological inflammation marker values do not exclude the presence of an infection, especially of the fingers. Our study suggests that crystal arthropathies may influence the CRP value more than local infections owing to their systemic pathomechanism and their highly inflammatory characteristic. At a cut-off level of 40 mg/L, the sensitivity and specificity for CRP in our patients were 0.77 and 0.65, respectively. Thus, CRP values above the cut-off level may indicate the presence of a disorder that mimics an infection. Joint aspiration may be justified to exclude the presence of crystals, especially in patients with mono-arthritic findings and a positive medical history. WBC, ESR and PCT do not need to be determined. For organizational reasons this study was not blinded, which had a direct effect on the level of evidence. Our findings therefore need confirmation in further studies.

EVALUATION OF THE FIRST METACARPAL PROXIMAL FACET INCLINATION AS A PROGNOSTIC PREDICTOR FOLLOWING ARTHROPLASTY FOR OSTEOARTHRITIS OF THE THUMB CARPOMETACARPAL JOINT

We have retrospectively reviewed 17 thumbs in 16 patients with osteoarthritis of the thumb carpometacarpal joints, for which arthroplasty was performed using Kaarelas method. Postoperatively, three thumbs in two patients had poor outcomes; both patients had a sharp slope of the base of the first metacarpal. Serial radiographic measurements suggested that this sharp slope affected the adducted position of the first metacarpal, and led to the appearance of a metacarpophalangeal joint hyperextension deformity of the thumb. This radiological finding could be a prognostic predictor after surgery for osteoarthritis of the thumb carpometacarpal joint.