A cadaveric study of ulnar nerve strain at the elbow associated with cubitus valgus/varus deformity.

BACKGROUND: Cubital tunnel syndrome can be caused by overtraction and dynamic compression in elbow deformities. The extent to which elbow deformities contribute to ulnar nerve strain is unknown. Here, we investigated ulnar nerve strain caused by cubitus valgus/varus deformity using fresh-frozen cadavers. METHODS: We used six fresh-frozen cadaver upper extremities. A strain gauge was placed on the ulnar nerve 2 cm proximal to the medial epicondyle of the humerus. For the elbow deformity model, osteotomy was performed at the distal humerus, and plate fixation was performed to create cubitus valgus/varus deformities (10°, 20°, and 30°). Ulnar nerve strain caused by elbow flexion (0-125°) was measured in both the normal and deformity models. The strains at different elbow flexion angles within each model were compared, and the strains at elbow extension and at maximum elbow flexion were compared between the normal model and each elbow deformity model. However, in the cubitus varus model, the ulnar nerve deflected more than the measurable range of the strain gauge; elbow flexion of 60° or more were considered effective values. Statistical analysis of the strain values was performed with Friedman test, followed by the Williams' test (the Shirley‒Williams' test for non-parametric analysis). RESULTS: In all models, ulnar nerve strain increased significantly from elbow extension to maximal flexion (control: 13.2%; cubitus valgus 10°: 13.6%; cubitus valgus 20°: 13.5%; cubitus valgus 30°: 12.2%; cubitus varus 10°: 8.3%; cubitus varus 20°: 8.2%; cubitus varus 30°: 6.3%, P < 0.001). The control and cubitus valgus models had similar values, but the cubitus varus models revealed that this deformity caused ulnar nerve relaxation. CONCLUSIONS: Ulnar nerve strain significantly increased during elbow flexion. No significant increase in strain 2 cm proximal to the medial epicondyle was observed in the cubitus valgus model. Major changes may have been observed in the measurement behind the medial epicondyle. In the cubitus varus model, the ulnar nerve was relaxed during elbow extension, but this effect was reduced by elbow flexion.

Acromioclavicular joint instability on cross-body adduction view: the biomechanical effect of acromioclavicular and coracoclavicular ligaments sectioning.

BACKGROUND: The acromioclavicular (AC) and coracoclavicular (CC) ligaments are important stabilizers of the AC joint. We hypothesized that AC and trapezoid ligament injuries induce AC joint instability and that the clavicle can override the acromion on cross-body adduction view even in the absence of conoid ligament injury. Accordingly, we investigated how sectioning the AC and CC ligaments contribute to AC joint instability in the cross-body adduction position. METHODS: Six fresh-frozen cadaveric shoulders were used in this study, comprising five male and one female specimen, with a mean age of 68.7 (range, 51-87) years. The left side of the trunk and upper limb, and the cervical and thoracic vertebrae and sternum were firmly fixed with an external fixator. The displacement of the distal end of the clavicle relative to the acromion was measured using an electromagnetic tracking device. We simulated AC joint dislocation by the sequential resection of the AC ligament, AC joint capsule, and CC ligaments in the following order of stages. Stage 0: Intact AC and CC ligaments and acromioclavicular joint capsule; stage 1: Completely sectioned AC ligament, capsule and joint disc; stage 2: Sectioned trapezoid ligament; and stage 3: Sectioned conoid ligament. The superior clavicle displacement related to the acromion was measured in the horizontal adduction position, and clavicle overriding on the acromion was assessed radiologically at each stage. Data were analyzed using a one-way analysis of variance and post-hoc tests. RESULTS: Superior displacement was 0.3 mm at stage 1, 6.5 mm at stage 2, and 10.7 mm at stage 3. On the cross-body adduction view, there was no distal clavicle overriding at stages 0 and 1, and distal clavicle overriding was observed in five cases (5/6: 83%) at stage 2 and in six cases (6/6: 100%) at stage 3. CONCLUSION: We found that AC and trapezoid ligament sectioning induced AC joint instability and that the clavicle could override the acromion on cross-body adduction view regardless of conoid ligament sectioning. The traumatic sections of the AC and trapezoid ligament may lead to high grade AC joint instability, and the distal clavicle may subsequently override the acromion.

Impacted intraarticular fragments of distal radius fractures: A radiographic characterization and analysis of reliability and diagnostic accuracy.

BACKGROUND: Reduction using ligamentotaxis may not be effective enough to treat impacted intraarticular fragments of distal radius fractures. Articular incongruence resulting from the loss of reduction is a risk factor for postoperative osteoarthritis and worse clinical outcome. This study aimed to analyze the radiographic characterization of the impacted intraarticular fragments of distal radius fractures using two/three-dimensional computed tomography (CT). Further, we assessed the reliability and diagnostic accuracy in detecting the fragments using plain radiographs. METHODS: We analyzed 167 three-dimensional CT images of the intraarticular distal radius fractures and selected 12 fractures with impacted intraarticular fragments. We recorded the location, size, and displacement of the fragment using CT images. In addition, six examiners evaluated 25 fractures including those 12 fractures having the fragments using plain radiographs for detecting the fragments and their displacements. Further, we evaluated the reliability and diagnostic accuracy of the plain radiographs in the detection of the fragment. RESULTS: Fifteen impacted intraarticular fragments were found in 12 wrists. The displacement of the scaphoid facet fragment was significantly larger than that of the lunate facet fragment in CT measurement (7.0 mm and 3.6 mm). Inter and intraobserver reliability of the diagnosis for the fragment in plain radiographs were poor and fair (κ: 0.14 and κ:0.27). Diagnostic accuracy in detecting the fragment in plain radiographs generated mean sensitivity: 0.4, mean specificity: 0.73, and mean accuracy: 0.58. The mean sensitivity in detecting a lunate facet fragment was lower than that of a scaphoid facet fragment in plain radiographs (0.24 and 0.44). CONCLUSION: Impacted intraarticular fragments were found in 7% of intraarticular distal radius fractures. We observed low reliability and sensitivity in detecting the fragment using plain radiographs. Preoperative recognition of the fragments using plain radiograph were difficult, even though the magnitude of step-off of the scaphoid facet fragment was large.

Soft-tissue reconstruction after soft-tissue sarcoma resection: the clinical outcomes of 24 patients.

PURPOSE: Pedicle or free-flap reconstruction is important in surgical sarcoma management. Free flaps are indicated only when pedicle flaps are considered inadequate; however, they are associated with a higher risk of flap failure, longer surgical times, and technical difficulty. To determine the skin defect size that can be covered by a pedicle flap, we investigated the clinical outcomes and complications of reconstruction using pedicle flaps vs. free flaps after sarcoma resection. METHODS: We retrospectively studied the medical records of 24 patients with soft-tissue sarcomas who underwent reconstruction using a pedicle (n = 20) or free flap (n = 4) following wide tumour resection. RESULTS: All skin defects of the knee, lower leg, and ankle were reconstructed using a pedicle flap. Skin defects of the knee, lower leg, and ankle were covered by up to 525 cm2, 325 cm2, and 234 cm2, respectively. The amount of blood loss was significantly greater in the free-flap group than in the pedicle flap group (p = 0.011). Surgical time was significantly shorter in the pedicle flap group than in the free-flap group (p = 0.006). Total necrosis was observed in one (25%) patient in the free-flap group; no case of total necrosis was observed in the pedicle flap group. CONCLUSION: Less blood loss, shorter surgical time, and lower risk of total flap necrosis are notable advantages of pedicle flaps over free flaps. Most skin defects, even large ones, of the lower extremities following sarcoma resection can be covered using a single pedicle flap or multiple pedicle flaps.

Partial Trapeziotrapezoid Resection and Thumb Range of Movement After Trapeziometacarpal Joint Fusion-A Biomechanical Study.

PURPOSE: Trapeziometacarpal (TMC) joint arthrodesis is an effective treatment for stage III osteoarthritis. Although this procedure alleviates thumb pain and restores grip power and pinch strength, persistent limitation of thumb movement is inevitable. This biomechanical study aimed to investigate the altered kinematics of thumb circumduction motion after TMC joint arthrodesis and subsequent excision of the trapeziotrapezoid (TT) and trapezio-second metacarpal (T-2MC) joint spaces. METHODS: Eight cadaver upper extremities were mounted on a custom testing apparatus. The hand and carpal bones were fixed to the apparatus, except for the first metacarpal bone, trapezium, and trapezoid. A 50-g load was applied at the tip of the first metacarpal head to generate passive thumb circumduction. An electromagnetic tracking system measured the angular and rotational displacement of the first metacarpal. All specimens were tested in 4 conditions: intact, after simulated TMC joint fusion, after subsequent excision of 3 mm of bone at the TT joint space, and after additional 3 mm resection at the T-2MC joint space. RESULTS: After simulated TMC arthrodesis, the range of angular motion of thumb circumduction decreased to 25% that of the intact thumb. Subsequent resections at the TT and T-2MC joint spaces increased circumduction ranges to 49% (TT joint) and 73% (TT plus T-2MC joints) that of the intact thumb. The range of thumb rotational motion showed a similar trend. CONCLUSIONS: Trapeziometacarpal arthrodesis decreased the range of both angular and rotational motion during thumb circumduction. Subsequent resections at the paratrapezial space increased the range of thumb motion, suggesting that hypermobility of the paratrapezial joints increases thumb mobility after TMC joint fusion. CLINICAL RELEVANCE: Patients with hypermobile paratrapezial joints may have larger thumb movement after TMC joint fusion. Additional resections of the TT and T-2MC joint spaces may further mobilize the thumb in patients who complain of stiffness after TMC fusion.

Vascularized pedicled bone graft from the distal radius supplied by the anterior interosseous artery for treatment of ulnar shaft nonunion: An anatomical study of cadavers and a case report.

BACKGROUND: A vascularized distal radius graft can be a reliable solution for the treatment of refractory ulnar nonunion. The aim of this study is to establish the anatomical basis of a vascularized bone graft pedicled by the anterior interosseous artery and report its clinical application, using cadaveric studies and a case report. METHODS: Fourteen fresh frozen cadaveric upper limbs were used. The branches of the anterior interosseous artery (the 2, 3 intercompartmental supraretinacular artery and the fourth extensor compartment artery) were measured at the bifurcation site. The anatomical relationship between the anterior interosseous artery and motor branches of the posterior interosseous nerve was investigated. An anterior interosseous artery pedicled bone flap was used in a 48-year-old woman with refractory ulnar nonunion. RESULTS: There were two variations depending on whether the 2,3 intercompartmental supraretinacular artery branched off distally or proximally from the terminal motor branch of the posterior interosseous nerve. The proximal border of the graft was located at an average of 10.5 cm (range, 6.5-12.5 cm) from the distal end of the ulnar head in the distal type (57%) and 17.5 cm (range, 9.5-21.5 cm) in the proximal type (43%). In the clinical application, successfully consolidation was achieved 4 months post-surgery. The patient had not developed any postoperative complications until the 2-year postoperative follow-up. CONCLUSIONS: The anterior interosseous artery-pedicled, vascularized distal radius bone graft would be a reliable alternative solution for the treatment of an ulnar nonunion located within the distal one-third of the ulna.

Arthroscopic Distal Scaphoid Resection for Isolated Scaphotrapeziotrapezoid Osteoarthritis.

PURPOSE: To investigate the radiographic and clinical results of arthroscopic distal scaphoid resection for isolated scaphotrapeziotrapezoid (STT) osteoarthritis and analyze the radiographic parameters associated with the functional outcomes. METHODS: From 2008 to 2014, 17 wrists with symptomatic isolated STT osteoarthritis without carpal deformity underwent arthroscopic distal scaphoid resection. We evaluated visual analog scale (VAS) scores for pain, grip strength, pinch strength, and Patient-Rated Wrist Evaluation (PRWE) scores before surgery and at the final follow-up. We analyzed correlations between the resection height and the radiographic and functional outcomes. RESULTS: The average follow-up period was 42 months. The average VAS score improved from 6.1 ± 2.3 before surgery to 1.7 ± 1.9 after surgery. The average grip strength improved from 18 ± 6 to 19 ± 9 kg, pinch strength from 2.5 ± 1.1 to 4.4 ± 1.7 kg, and PRWE score from 52 ± 23 to 32 ± 24. Carpal deformity (C-L angle of > 15°) was seen in 2 patients at the final follow-up. The deformity was more likely to occur when the resection height was greater than 3 mm. CONCLUSIONS: Arthroscopic distal scaphoid resection alone can reduce pain and improve functional outcomes for early to mid-stage isolated STT osteoarthritis in patients without dorsal intercalated segment instability deformity. Resection of greater than 3 mm of the distal scaphoid may result in carpal malalignment. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Predictors of Hand Dexterity after Single-Digit Replantation.

BACKGROUND: Microsurgical replantation of the thumb and digits has become an increasingly familiar technique in clinical practice worldwide. However, successful digit replantation does not always provide better hand function than revision amputation. Little information is available regarding predictors of motor skill activities of replanted hands. Therefore, we retrospectively evaluated hand dexterity after single-digit replantation at a minimum follow-up of 1 year and analyzed the factors influencing dexterity. METHODS: This retrospective cohort study included 23 patients treated for amputation injuries at our institution from 2014 to 2015. Patients with amputations from Tamai's zone 2 to 5 of the thumb (3 patients), index finger (11 patients), or middle finger (9 patients) who underwent digital replantation surgery and were followed up for more than 1 year were included. Follow-up evaluations were conducted at an average of 23 months postoperatively (range: 13-25 months). We hypothesized that possible factors influencing hand dexterity after single-digit replantation were patient age, injured finger, key pinch strength, Semmes-Weinstein test result, and percentage of total active motion. Relationships between the outcome variable, which was the result of the Purdue Pegboard Test of hand dexterity, and explanatory variables were analyzed using Spearman's correlation coefficient. A p-value of < 0.05 indicated statistical significance. RESULTS: No postoperative complications occurred. Univariate analysis indicated that decreased hand dexterity after single-digit replantation was significantly associated with older age (p = 0.001) and poor recovery of sensation, as shown by the Semmes-Weinstein test (p = 0.012). CONCLUSION: Patient age was a risk factor for low hand dexterity after replantation surgery. Recovery of finger sensitivity enhanced dexterity of motor skill activities following finger replantation surgery.

Magnetic resonance imaging analysis of the extensor carpi ulnaris tendon and distal radioulnar joint in triangular fibrocartilage complex tears.

BACKGROUND: We compared the incidence of extensor carpi ulnaris (ECU) tendon and distal radioulnar joint (DRUJ) abnormalities using magnetic resonance imaging (MRI) between patients with triangular fibrocartilage complex (TFCC) tears and subjects without ulnar wrist pain. Additionally, we aimed to identify potential predictors of these MRI lesions. METHODS: The TFCC group comprised 70 consecutive patients with TFCC tears. The control group comprised 70 age- and sex-matched subjects without ulnar wrist pain. We evaluated the presence or absence of fluid collection in the DRUJ and ECU peritendinous area and longitudinal ECU tendon splitting. Dimensions of the fluid collection area around the ECU tendon were measured to evaluate the severity. The incidences of these abnormal MRI findings were compared between the two groups. We analyzed the correlation between the presence of ECU tendon and DRUJ lesions and variables including age, magnitude of ulnar variance, and type of TFCC tear. RESULTS: Significant differences were found between the two groups in the incidence of fluid collection of the DRUJ and ECU peritendinous area, and longitudinal ECU tendon splitting. Among the 70 patients with TFCC tears, age and the magnitude of ulnar variance were significantly correlated with the severity of fluid collection around the ECU tendon. The magnitude of ulnar variance in patients with DRUJ fluid collection was significantly larger than that in patients without fluid collection. There was a significant correlation between the presence of disc tears and DRUJ fluid collection. CONCLUSION: We found a higher incidence of accompanying abnormal MRI findings of the ECU tendon and DRUJ in patients with TFCC tears than in the control group. The presence of disc tears, the magnitude of ulnar variance, and age may be risk factors for these MRI lesions associated with TFCC tears.

Supplying osteogenesis to dead bone using an osteogenic matrix cell sheet.

PURPOSE: To evaluate whether osteogenic matrix cell sheets can supply osteogenesis to dead bone. METHODS: Femur bone fragments (5 mm in length) were obtained from Fisher 344 rats and irradiated by a single exposure of 60 Gy to produce bones that were no longer viable. Osteogenic matrix cell sheets were created from rat bone marrow-derived stromal cells (BMSCs). After wrapping the dead bone with an osteogenic matrix cell sheet, it was subcutaneously transplanted into the back of a rat and harvested after 4 weeks. Bone formation around the dead bone was evaluated by X-ray imaging and histology. Alkaline phosphatase (ALP) and osteocalcin (OC) mRNA expression levels were measured to confirm osteogenesis of the transplanted bone. The contribution of donor cells to bone formation was assessed using the Sry gene and PKH26. RESULTS: After the cell sheet was transplanted together with dead bone, X-ray images showed abundant calcification around the dead bone. In contrast, no newly formed bone was seen in samples that were transplanted without the cell sheet. Histological sections also showed newly formed bone around dead bone in samples transplanted with the cell sheet, whereas many empty lacunae and no newly formed bone were observed in samples transplanted without the cell sheet. ALP and OC mRNA expression levels were significantly higher in dead bones transplanted with cell sheets than in those without a cell sheet (P < 0.01). Sry gene expression and cells derived from cell sheets labeled with PKH26 were detected in samples transplanted with a cell sheet, indicating survival of donor cells after transplantation. CONCLUSION: Our study indicates that osteogenic matrix cell sheet transplantation can supply osteogenesis to dead bone.

Biomechanical study of isolated radial head dislocation.

BACKGROUND: Isolated radial head dislocation is a rare injury with an unclear pathomechanism, and the treatment is controversial. The purpose of the present study was to investigate the biomechanical contributions of the annular ligament, quadrate ligament, interosseous membrane, and annular ligament reconstructions to proximal radioulnar joint stability. METHODS: Five fresh frozen cadaveric upper extremities were amputated above the elbow and solidly fixed on a customized jig. Radial head dislocation was reproduced by sequential sectioning of ligamentous structures and passive mobility testing. Radial head displacement during mobility testing was measured with an electromagnetic tracking device in three forearm rotation positions. The data were compared among different sectioning stages and between two types of simulated ligamentous reconstruction. RESULTS: Lateral displacement of the radial head significantly increased in the neutral forearm rotation after annular ligament sectioning (46 ± 10%, p < 0.05). After quadrate ligament sectioning, we found significant posterior (67 ± 36%, p < 0.05) and lateral (74 ± 24%, p < 0.01) displacement in neutral forearm rotation and pronation. Significant radial head displacement was found in all directions and in all forearm positions after sequential sectioning of the proximal half of the interosseous membrane. Anatomical annular ligament reconstruction stabilized the proximal radioulnar joint except for anterior laxity in neutral forearm rotation (15 ± 6%, p < 0.05). The radial head with Bell Tawse procedure was significantly displaced in all directions. CONCLUSION: The direction of radial head instability varied depending on the degree of soft tissue sectioning and specific forearm rotation. Anterior radial head dislocation may involve more severe ligament damage than other types of dislocation. Anatomical annular ligament reconstruction provided multidirectional radial head stability.

Arthroscopic Partial Capitate Resection for Type Ia Avascular Necrosis: A Short-Term Outcome Analysis.

PURPOSE: To examine short-term clinical results of arthroscopic partial resection for type Ia avascular necrosis of the capitate. METHODS: Patients who underwent arthroscopic treatment for type 1a avascular necrosis of the capitate with at least 1-year follow-up were identified through a retrospective chart review. The necrotic capitate head was arthroscopically resected with removal of the lunate facet and preservation of the scaphoid and hamate facets. Wrist range of motion, grip strength, and radiographic parameters--carpal height ratio, radioscaphoid angle, and radiolunate angle-were determined before surgery and at the latest follow-up. Patients completed a visual analog scale for pain; Disabilities of the Arm, Shoulder, and Hand measure; and the Patient-Rated Wrist Evaluation score before surgery and at the latest follow-up. RESULTS: Five patients (1 male, 4 females) with a mean age of 34 years (range, 16-49 years) and a mean follow-up duration of 20 months (range, 12-36 months) were identified during the chart review. All were type Ia (Milliez classification). Arthroscopy revealed fibrillation or softening with cartilage detachment at the lunate facet of the capitate head and an intact articular surface at the scaphoid and hamate facet. At the latest follow-up, the mean wrist flexion-extension was 123° (vs 81° before surgery) and grip strength was 74% (vs 37% before surgery). The visual analog scale score for pain; the Disabilities of the Arm, Shoulder, and Hand score; and the Patient-Rated Wrist Evaluation score before surgery showed a significant improvement following treatment. Radiographic parameters did not significantly change at the final follow-up, although the proximal carpal row trended toward flexion. CONCLUSIONS: Arthroscopic partial resection of the capitate head was an acceptable treatment for type Ia avascular necrosis of the capitate. It provided adequate pain relief and improved the range of wrist motion and grip strength during short-term follow-up. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Dynamic analysis of the ulnar nerve in the cubital tunnel using ultrasonography.

BACKGROUND: We investigated the dynamics of the ulnar nerve during elbow flexion and the relationships between these dynamics and the morphology of the ulnar nerve groove in healthy individuals. MATERIALS AND METHODS: Twenty healthy volunteers (40 elbows) underwent ultrasonographic examination of the ulnar nerve at the elbow. We measured the breadth and depth of the ulnar nerve groove at 90° of elbow flexion and calculated the depth-to-breadth ratio. We recorded the distance from the trochlea of the humerus to the nerve and the short-axis diameter of the nerve at 30°, 60°, 90°, and 120° of elbow flexion. We calculated the medial shift and flattening of the ulnar nerve at each angle relative to 30° of flexion, compared the values among the different angles, and compared the depth-to-breadth ratio with the location, medial shift, and flattening ratio of the ulnar nerve. RESULTS: The medial shift was significantly greater at 120° than at other angles (P < .001). Flattening increased with increasing elbow flexion and was significantly different at 60°, 90°, and 120° (all P < .001). The flattening ratios were significantly correlated with the depth-to-breadth ratio at 120° (r = -0.43, P = .005). CONCLUSIONS: The ulnar nerve moves medially and is flattened with the elbow flexed between 90° and 120°. When the ulnar nerve groove is shallow, high degrees of elbow flexion result in flattening of the ulnar nerve in the groove.

Coverage of lateral soft tissue defects with sartorius muscle flap after distal femoral replacement for malignant bone tumors.

INTRODUCTION: To prevent infection after limb-sparing surgery for primary malignant bone tumors, it is important to cover the megaprosthesis with muscle tissue that has sufficient blood flow. Coverage with a lateral gastrocnemius flap has been reported in cases of distal femoral replacement in which the vastus lateralis and vastus intermedius muscles have been resected; however, the risk of peroneal nerve palsy is reportedly high because the muscle flap passes near the peroneal head. This study was performed to examine the postoperative outcomes of patients with primary malignant bone tumors of the distal femur who underwent wide resection (including the vastus lateralis and vastus intermedius muscles) followed by reconstruction with a megaprosthesis and coverage of the lateral side of the prosthesis with a sartorius muscle flap. METHODS: We retrospectively analyzed three patients who underwent reconstruction with a megaprosthesis after wide resection of a primary malignant bone tumor of the distal femur involving the vastus lateralis and vastus intermedius muscles and reconstruction of the soft tissue defect on the lateral side of the prosthesis with a sartorius muscle flap. RESULTS: The average defect size was 6 × 13 cm, the average time required for a sartorius muscle flap was 100 min, and the average implant coverage was 93%. The average postoperative follow-up period was 35 months, during which no postoperative complications such as infection, skin necrosis, or nerve palsy occurred. DISCUSSION: The distally based sartorius muscle flap is easy to elevate in the supine position, has minimal functional loss after harvesting, and has minimal risk of nerve palsy. It can be advocated as the first option for coverage of soft tissue defects lateral to distal femoral replacement.

Osteogenesis of cryopreserved osteogenic matrix cell sheets.

Cryopreservation of tissue engineered bone (TEB), whilst maintaining its osteogenic ability, is imperative for large-scale clinical application. We previously reported a novel cell transplantation method, in which bone-marrow-derived mesenchymal stem cells (BMSCs) were cultured to confluence and differentiated down the osteogenic lineage to form osteogenic matrix cell sheets (OMCS). OMCS have high alkaline phosphatase (ALP) activity and osteocalcin (OC) contents and can be easily used for producing TEB. The aim of the present study was to investigate whether TEB produced by cryopreserved OMCS maintains sufficient osteogenic potential in vivo. OMCS were prepared and divided into three groups according to storage period of cryopreservation (fresh (no cryopreservation), 4 week and 12 week cryopreservation groups). OMCS were cryopreserved by storage in freezing medium (Cell Banker 1®) at -80 °C. Cryopreserved OMCSs were rapidly thawed at room temperature and wrapped around Hydroxyapatite (HA) scaffolds prior to implantation into subcutaneous sites in rats, to determine their in vivo bone-forming capability. The constructs were harvested 4 weeks after transplantation and examined histologically and biochemically. Histological analysis of the constructs showed extensive bone formation in the HA pores with high ALP activity and OC content detected in the cryopreservation groups. The present study clearly indicates that cryopreserved/thawed OMCS are still capable of producing mineralized matrix on scaffolds, resulting in bone formation. This cryopreservation technique could be applied for hard tissue reconstruction to ease the cell preparation method prior to time of use.

Intra-articular distal radius fractures involving the distal radioulnar joint (DRUJ): three dimensional computed tomography-based classification.

PURPOSE: The purpose of this study was to analyze fracture patterns and the magnitude of displacement in the distal radioulnar joint (DRUJ), by three-dimensional (3D) computed tomography (CT), for distal radius fractures with intra-articular displacement of the radiocarpal joint. METHODS: We reconstructed 3D images for 72 consecutive patients with displaced intra-articular distal radius fracture on the basis of fine-cut axial CT data. The fracture patterns involving the DRUJ were classified on the basis of the location and direction of fracture lines, and the extent of fracture comminution. We measured the maximum spatial distance of the gap and the step between the fragments in each 3D image, and the magnitudes of displacement between the groups were compared by analysis of variance followed by post-hoc analysis by use of Tukey's test. RESULTS: Sixty wrists had a fracture involving the DRUJ. We classified the 60 wrists into 3 types of fracture pattern. Type 1 was a transverse fracture with minimum displacement. Type 2, in which fracture lines extended into the distal margin of the sigmoid notch, was the most common longitudinal fracture. Type 3 was a fracture with multiple fragments. The step and gap in Type 3 was significantly larger than that in the other types. CONCLUSIONS: Eighty-three percent of intra-articular distal radius fractures had DRUJ involvement, and 28% of the wrists had multiple fragments. For Type 3 fractures with dorsal or proximal comminution displacement was significantly larger than for simple Type 1 and 2 fractures. Surgical intervention for the DRUJ fragment may be beneficial when there is remarkable intra-articular displacement.

A successful reconstruction using a frozen autograft and a pedicled latissimus dorsi flap after a S12345B shoulder girdle resection in a patient with osteosarcoma.

We present a case of high-grade osteosarcoma in the proximal humerus in an 8-year-old boy. Massive tumor expansion required a S12345B shoulder girdle resection according to the system of the Musculoskeletal Tumor Society. After wide resection, only a small portion of the distal humerus and none of the rotator cuff muscles would be spared. Because the humeral portion would be too short to support the stem and the soft tissue would be insufficient to cover prosthetic components, we designed a composite reconstruction using a frozen autograft and a pedicled muscle flap. At 2 years postoperatively, our patient exhibited good adaptation and had acquired fine dexterity of the upper limb. To our knowledge, this is the first report regarding a successful composite reconstruction after a S12345B shoulder girdle resection.

Simultaneous Bilateral Chronic Volar Lunate Dislocation: A Case Report.

CASE: A 24-year-old professional judo competitor suffered injuries to both the wrists when he fell on his back while lifting a 90-kg barbell in the bilateral dorsiflexed wrist position. Simultaneous bilateral volar lunate dislocation had been missed for a year. The degenerated lunates were simultaneously removed using a palmar approach. At 12 months postoperatively, the patient returned to judo competitions without pain. Radiography showed no progression of the intercarpal alignment abnormality. CONCLUSION: Simultaneous bilateral chronic volar lunate dislocation is extremely rare. Long-term follow-up is necessary to check for carpal alignment.

Treatment of painful median nerve neuroma using pedicled vascularized lateral antebrachial cutaneous nerve with adipofascial flap: a cadaveric study and exploration of clinical application.

The most common procedure for the treatment of painful median nerve neuroma is coverage with vascularized soft tissue following external neurolysis. However, the ideal treatment should include reconnecting the proximal and distal stumps of the damaged nerve to allow the growth of regenerating axons to their proper targets for a functional recovery. We developed a useful technique employing radial artery perforator adipofascial flap including the lateral antebrachial cutaneous nerve (LABCN) to repair the median nerve by vascularized nerve grafting and to achieve coverage of the nerve with vascularized soft tissue. In an anatomical study of 10 fresh-frozen cadaver upper extremities, LABCN was constantly bifurcated into two branches at the proximal forearm (mean: 8.2 cm distal to the elbow) and two branches that run in a parallel manner toward the wrist. The mean length of the LABCN branches between the bifurcating point and the wrist was 18.2 cm, which enabled inclusion of adequate length of the LABCN branches into the radial artery perforator adipofascial flap. The diameters of the LABCN branches (mean: 1.7 mm) were considered suitable to bridge the funiculus of the median nerve defect after microsurgical internal neurolysis. In all cadaver upper extremities, the 3-cm median nerve defect at the wrist level could be repaired using the LABCN branches and covered with the radial artery perforator adipofascial flap. On the basis of this anatomical study, the median nerve neuroma was successfully treated with radial artery perforator adipofascial flap including vascularized LABCN branches.