Shinsuke Omori

3-Dimensional Prebent Plate Fixation in Corrective Osteotomy of Malunited Upper Extremity Fractures Using a Real-Sized Plastic Bone Model Prepared by Preoperative Computer Simulation

PURPOSE To assess the clinical outcome and accuracy of prebent plate fixation in corrective osteotomy for malunited upper extremity fractures using a plastic bone model manufactured by preoperative computer simulation. METHODS Nine consecutive patients underwent computed tomography (CT)-based 3-dimensional corrective osteotomy for malunited upper extremity fractures. There were 4 cubitus varus deformities, 1 cubitus valgus deformity, and 4 forearm diaphyseal malunions. We constructed a computer model of the affected bones using the CT data and simulated the 3-dimensional deformity correction on a computer. A real-sized plastic model of the corrected bone was manufactured by rapid prototyping. We used a metal plate, prebent to fit the plastic bone model, in the actual surgery. Patients were evaluated after an average follow-up of 22 months (range, 14-36 mo). We retrospectively collected radiographic and clinical data at the most recent follow-up and compared them with preoperative data. We also performed CT after surgery and evaluated the error in corrective osteotomy as the difference between preoperative simulation and postoperative bone model. RESULTS The range of forearm rotation and grip strength in patients with forearm malunions improved after corrective osteotomies of the radius and ulna. Wrist pain, which 2 patients with forearm malunion had experienced before surgery, disappeared or decreased substantially after surgery. Radiographic examination indicated that preoperative angular deformities were nearly nonexistent after all corrective osteotomies. Three-dimensional errors in the corrective osteotomy using a prebent plate, as evaluated by CT data, were less than 3 mm and 2°. CONCLUSIONS Prebent plate fixation in corrective osteotomy for malunited upper extremity fractures using a 3-dimensionally corrected, real-sized plastic bone model prepared by preoperative computer simulation is a precise and relatively easily performed technique that results in satisfactory clinical outcome. TYPE OF STUDY/LEVEL OF EVIDENCE Therapeutic IV.

Influence of Ulnar Translation of the Radial Shaft in Distal Radius Fracture on Distal Radioulnar Joint Instability

It has been reported that the distal interosseous membrane (DIOM) of the forearm constrains the dorsal dislocation of the distal radius. A residual ulnar translation deformity of the radial shaft in distal radius fractures has the potential to cause distal radioulnar joint (DRUJ) instability when triangular fibrocartilage complex (TFCC) injury is also present, because it may result in detensioning of the DIOM. Correction of ulnar translation of the radial shaft is critical because it restores DIOM tension, which then firmly holds the ulnar head in the concavity of the sigmoid notch.

Postoperative accuracy analysis of three-dimensional corrective osteotomy for cubitus varus deformity with a custom-made surgical guide based on computer simulation

BACKGROUND For correction of cubitus varus deformity resulting from supracondylar fracture of the humerus, we developed an operative method with use of a custom-made surgical guide, designed on the basis of 3-dimensional (3D) computer simulation with computed tomography data. The purpose of this study was to investigate the postoperative accuracy of this system in clinical cases. METHODS Subjects included 17 consecutive patients (13 males and 4 females) with cubitus varus deformity after supracondylar fracture. Patients underwent 3D corrective osteotomy with use of a custom-made surgical guide. Postoperative computed tomography scan was performed after bone union diagnosis on plain radiographs, and postoperative 3D bone models were compared with preoperative simulation by surface registration technique. In addition, we evaluated radiographic parameters (humerus-elbow-wrist angle and tilting angle) and range of elbow motion at the most recent follow-up. RESULTS Mean errors in 3D corrective osteotomy were 0.6° ± 0.7° in varus-valgus rotation, 0.8° ± 1.3° in flexion-extension rotation, 2.9° ± 2.8° in internal-external rotation, 1.7 ± 1.8 mm in anterior-posterior translation, 1.3 ± 1.8 mm in lateral-medial translation, and 7.1 ± 6.3 mm in proximal-distal translation. The mean humerus-elbow-wrist angle on plain radiographs of the affected side was 15° in varus before surgery and improved to 6° in valgus after surgery. The mean tilting angle of the affected side was 31° before surgery and improved to 40° after surgery. CONCLUSION The 3D correction of cubitus varus deformity was performed accurately within the allowable error limits.

Three-dimensional corrective osteotomy using a patient-specific osteotomy guide and bone plate based on a computer simulation system: accuracy analysis in a cadaver study

The accuracy of three‐dimensional (3‐D) corrective osteotomy using a patient‐specific osteotomy guide and bone plate based on computer simulation was investigated.

Does cubitus varus cause morphologic and alignment changes in the elbow joint

BACKGROUND In cubitus varus after pediatric supracondylar fracture, late development of trochlear deformity causing additional varus angulation and joint misalignment relating to late complications of the tardy ulnar nerve palsy or posterolateral rotatory instability have been suggested. However, it is unclear whether these morphologic and alignment changes of the elbow joint occur in cubitus varus. The object of this study was to investigate morphologic changes of the bones and alignment changes of the elbow joint in longstanding cubitus varus using 3-dimensional computer bone models created from computed tomography data. MATERIALS AND METHODS We studied 14 patients with longstanding cubitus varus after pediatric supracondylar fractures. Three-dimensional bone models of the bilateral humerus, radius, and ulna were created from computed tomography data. We compared the morphology and alignment of the elbow joint between the affected side and contralateral unaffected side. RESULTS The posterior trochlea, distal part of the lateral capitellum, diameters of the radial head, and articular surface of the ulna in cubitus varus were larger than those of the contralateral elbow. In the ulna, the convex portion of the trochlear notch shifted laterally in cubitus varus. Joint alignment in cubitus varus was affected by a shift of the ulna to a more distal and medial position with external rotation and flexion. CONCLUSIONS In longstanding cubitus varus, the morphology and alignment of the elbow joint are observed to differ from those of the normal side.

The association between cubital tunnel morphology and ulnar neuropathy in patients with elbow osteoarthritis

BACKGROUND Morphologic changes in the cubital tunnel during elbow motion in patients with elbow osteoarthritis have not been examined in vivo. We examined changes in cubital tunnel morphology during elbow motion and characteristics of medial osteophyte development to elucidate whether cubital tunnel area and medial osteophyte size are factors contributing to cubital tunnel syndrome in patients with elbow osteoarthritis. METHODS We performed computed tomography of 13 primary osteoarthritic elbows in patients with cubital tunnel syndrome (group A) and 25 primary osteoarthritic elbows in patients without cubital tunnel syndrome (group B) at full extension, 90° of flexion, and full flexion. Cubital tunnel area, humeral and ulnar osteophyte area, and proportion of osteophytes within the cubital tunnel were analyzed at each position. RESULTS Humeral osteophytes and osteophyte proportion within the cubital tunnel were larger at full flexion (24.7 mm(2) and 49.9% in group A; 18.7 mm(2) and 39% in group B) and 90° of elbow flexion (20.3 mm(2) and 45.3% in group A; 10.2 mm(2) and 30.2% in group B) than at full extension (9.0 mm(2) and 31.3% in group A; 2.3 mm(2) and 12.5% in group B). These parameters were significantly greater in group A than in group B at full extension and 90° of flexion. CONCLUSIONS The effect of medial osteophytes on the ulnar nerve, especially on the humeral side, rather than narrowing of the cubital tunnel, may be a causative factor for cubital tunnel syndrome with elbow osteoarthritis.

Effect of wrist position on distal radioulnar joint stability: A biomechanical study

We investigated distal radioulnar joint (DRUJ) stability in different wrist positions and examined the relative contribution of each ligamentous component of the triangular fibrocartilage complex (TFCC) to DRUJ stability. We used nine fresh‐frozen cadavers. The humerus and ulna were fixed at 90° elbow flexion. The radiocarpal unit was translated relative to the ulna in dorsopalmar directions with the wrist in five positions. Displacement of the unit was measured by an electromagnetic tracking device. Magnitudes of displacement were compared between different wrist positions in various sectioning stages: ulnocarpal ligament (UCL) sectioning, radioulnar ligaments (RUL) sectioning, and extensor carpi ulnaris (ECU) floor sectioning. Wrist position and sectioning stage significantly influenced the displacement. In intact wrists, the displacement in wrist extension was significantly lower than that in neutral. However, after UCL sectioning, there were no longer any significant differences. After RUL sectioning, the displacement in radial deviation was significantly lower than that in neutral. Following ECU floor sectioning, there were no longer any significant differences. Thus, in intact wrists, DRUJ stability in wrist extension is likely due to tightening of the UCL. After complete RUL sectioning, DRUJ is stabilized in radial deviation due to tightening of the ECU floor.

In Vivo 3-Dimensional Analysis of Dorsal Intercalated Segment Instability Deformity Secondary to Scapholunate Dissociation: A Preliminary Report

PURPOSE To investigate in vivo 3-dimensional patterns of dorsal intercalated segment instability deformity resulting from scapholunate dissociation. METHODS We studied 6 patients with stage IV scapholunate dissociation in which there were complete tears of the scapholunate interosseous ligament and dorsal intercalated segment instability deformity. Of these, 3 patients had a dorsally displaced distal radius malunion, a condition known to aggravate or produce a dorsal intercalated segment instability deformity. With the wrist in neutral, we created 3-dimensional bone models of the wrists from computed tomography. We calculated centroid locations of each carpal and the rotational angle of the scaphoid and lunate relative to the radius and compared them with those of 6 normal subjects. The joint contact area was visualized to evaluate congruity of the radiocarpal and midcarpal joints. RESULTS In the scapholunate dissociated wrists, the scaphoid translated dorsally and radially with rotation in the direction of flexion and pronation. The lunate was extended and supinated. The capitate, trapezoid, and trapezium translated dorsally. Contact area of the radioscaphoid joint shifted dorsoradially owing to dorsoradial subluxation of the scaphoid proximal pole. Congruity was retained in the radiolunate, lunocapitate, and scaphotrapeziotrapezoid joints. In the malunion cases, the scaphoid and distal carpal rows translated more dorsally along dorsal angulation of the distal radius; therefore, incongruity of the radioscaphoid joint became more pronounced. CONCLUSIONS Dorsoradial subluxation of the scaphoid proximal pole over the dorsal rim of the radius led to incongruity of the radioscaphoid joint. Dorsal translation of the distal carpal row occurred with maintaining congruency of the radiolunate, lunocapitate, and scaphotrapeziotrapezoid joints. These results suggest that for realignment of the carpal axis of an advanced scapholunate dissociated wrist, we should restore scapholunate rotational malalignment and reduce the dorsally translated distal carpal row back to the anatomical position.

Surgery With Vascular Reconstruction for Soft-Tissue Sarcomas in the Inguinal Region: Oncologic and Functional Outcomes

BACKGROUND Treatment of soft-tissue sarcomas involving the inguinal region remains challenging because of difficulties in achieving wide surgical margins due to anatomical features. The study aimed to analyze the oncologic and functional outcomes of wide resection with vascular reconstruction for inguinal soft-tissue sarcomas. METHODS Three men and seven women were treated for inguinal soft-tissue sarcomas by wide surgical resection with vascular reconstruction. RESULTS Arteries and veins were replaced in nine patients, and artery replacement alone was carried out in one patient. Femoral nerve resections were performed in six patients. One patient and five patients developed local recurrence and distant metastases, respectively. Limb salvage was achieved in 9 of 10 patients (90%). Six patients and one patient developed vascular (arterial graft occlusion [n = 1], lymphedema [n = 5]) and nonvascular (hematoma [n = 1]) complications, respectively. Five-year arterial primary patency was 77%. Five-year disease-free and overall survival rates were 45% and 77%, respectively. Functional outcome scores at latest follow-up averaged 87.5% for Musculoskeletal Tumor Society 1993. CONCLUSIONS En-bloc resection of major critical structures along with tumor and vascular reconstructions using synthetic grafts is a feasible option in limb salvage surgery for inguinal soft-tissue sarcomas.

Limb salvage operation using intraoperative extracorporeal autogenous irradiated bone and tendon graft for myxoid liposarcoma on dorsum of foot

Foot and ankle sarcomas are conventionally treated with amputation. In this article, we report a case of myxoid liposarcoma on the dorsum of the foot treated by limb salvage operation with intraoperative extracorporeal autogenous irradiated bone and tendon grafts. The patient was a 76-year-old woman with a soft tissue tumor beneath the extensor tendons with attachment to the tarsal and metatarsal bones. The histological diagnosis was myxoid liposarcoma. Wide margin was achieved by splitting the tarsal and metatarsal bones into dorsal and plantar parts. The dorsal part of the bones and tendons was isolated from the resected material, irradiated ex-vivo and re-implanted into the hosts bones and tendons. No local recurrence was detected around the irradiated bones and tendons during the follow-up at 36 months. The functional rating was 74% according to the ISOLS rating system. This method may be a better procedure for limb salvage operation of sarcomas on the dorsum of the foot.