In vivo three-dimensional elbow biomechanics during forearm rotation.

BACKGROUND: It is unclear how elbow kinematics changes during forearm rotation. This study investigated in vivo 3-dimensional elbow kinematics during forearm rotation. METHODS: We studied 12 normal elbows using in vivo 3-dimensional computed tomography data in maximum forearm supination, neutral, and maximum pronation with the elbows in extension. We measured the motion of the radius and ulna relative to the humerus using a markerless bone registration technique and the contact area of the radiocapitellar joint, proximal radioulnar joint, and ulnohumeral joint using a proximity mapping method. RESULTS: When the forearm rotated from the supinated position to the pronated position, the radius showed significant varus rotation, internal rotation, and extension relative to the humerus. The center of the radial head significantly translated anteriorly, proximally, and laterally. The ulna significantly rotated in valgus, and the deepest point on the sagittal ridge of the trochlear notch translated medially with forearm pronation. The contact area of the radiocapitellar joint was largest in pronation. The contact area of the proximal radioulnar joint was largest in supination. The contact area of the ulnohumeral joint showed no significant change during forearm rotation. CONCLUSIONS: In pronation, because of the proximal migration of the radial head, the radiocapitellar joint was most congruent compared with other positions. The proximal radioulnar joint was most congruent in supination. The ulnohumeral joint congruency was not affected by forearm rotation. This study provides useful information for understanding 3-dimensional elbow motion and joint osseous stability related to forearm rotation.

Three-dimensional suitability assessment of three types of osteochondral autograft for ulnar coronoid process reconstruction.

BACKGROUND: Osteochondral autografts with use of the olecranon tip, lateral radial head, or proximal radial head have been employed for coronoid process reconstruction. However, it is unclear which autograft is most suitable for coronoid articular configuration. We assessed 3-dimensional articular facet suitability of 3 osteochondral autografts for coronoid process reconstruction. METHODS: We performed 3-dimensional computed tomography of 20 elbows to compare the articular facet configuration between the coronoid process and the ipsilateral olecranon tip, lateral radial head, and proximal radial head. We measured the area of the proximity region (≤2.0 mm) between the articular facets of the coronoid process and 3 osteochondral autografts, the covering rate defined as the percentage area of the coronoid articular facet occupied by the proximity region, the location of the proximity region center, and the percentage of the removed ulnohumeral articular facet. RESULTS: The covering rate was significantly higher with an olecranon graft than with radial head grafts. The regional center of a proximal radial head graft was significantly medial compared with that of olecranon and lateral radial head grafts. The olecranon graft used an average of 13.8% of the ulnohumeral articular facet. CONCLUSIONS: An olecranon graft was most suitable for defects of the coronoid process involving the tip, and a proximal radial head graft was most suitable for defects of the coronoid process involving the anteromedial rim. The use of an olecranon graft for reconstruction of 50% of the height of the coronoid process does not cause concern for gross elbow instability.

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.

Morphological evaluation of the distal interosseous membrane using ultrasound.

Evidence from a recent cadaveric study has revealed that the thickness of the distal interosseous membrane (DIOM) of the forearm shows substantial individual variations, and a thick fibrous tissue known as the distal oblique bundle (DOB) was found in 40% specimens in the study. Another cadaveric study revealed that greater stability of the distal radioulnar joint (DRUJ) was obtained in a group with DOB following ulnar shortening than in a group without DOB. Thus, the presence of DOB influences the condition of DIOM and the ability of DIOM to provide stability to the compromised DRUJ. In the present study, we carried out a preoperative morphological evaluation of DIOM using ultrasound (US) and compared the US findings with intraoperative findings in order to investigate the efficacy and the meanings of this US evaluation. A total of 14 patients with various diseases or injuries of the distal forearm requiring corrective surgery were enrolled. The mean values of DIOM thickness as measured by US evaluation correlated well with those measured intraoperatively. The sensitivity of US evaluation in confirming presence of DOB was 80% when the presence of DOB bundle was judged by DIOM thickness. In addition, 4 of 5 patients with chronic DRUJ instability showed no DOB. This study suggested that US can be a useful tool in evaluating DIOM and for detecting the presence of DOB and may provide helpful information regarding DRUJ instability.

Cylindrical corrective osteotomy for Madelung deformity using a computer simulation: case report.

We report an adolescent patient with Madelung deformity that we successfully treated by cylindrical corrective osteotomy of the distal radius. We used customized surgical guides, which were designed based on preoperative 3-dimensional computer simulation.

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.

Kinematic changes in elbow osteoarthritis: in vivo and 3-dimensional analysis using computed tomographic data.

PURPOSE: To investigate in vivo 3-dimensional kinematics in elbow osteoarthritis. We hypothesized that normal kinematics is preserved in an osteoarthritic elbow with a normal radiocapitellar joint (OAN). Conversely, we hypothesized that an osteoarthritic elbow with radiocapitellar degenerative changes (OAD) would show an abnormal kinematics pattern. Furthermore, the differences in osteophyte formation between groups may affect elbow kinematics. METHODS: We examined 7 normal elbows, 7 OAN elbows, and 9 OAD elbows. We investigated 3-dimensional kinematics using computed tomography registration techniques. The osteophyte location was determined using 3-dimensional bone models generated from computed tomography data. RESULTS: The kinematics is different in OAN and OAD elbows. In the OAN group, the ulna changed by 11° from a valgus to a varus position during elbow flexion and demonstrated a 4° change in the axis of elbow motion, similar to that in normal elbows. Osteophytes formed medially on the olecranon fossa. In the OAD group, the ulna changed by 4° varus during flexion from the 90° position, but only by 2° valgus during elbow extension from 90°. The change in the axis of elbow motion was 9°. Additional osteophytes formed on the anteromedial and lateral trochlea, lateral olecranon fossa, and medial olecranon of the ulnotrochlear joint, and on the radiocapitellar joint. CONCLUSIONS: Normal kinematics was preserved in the OAN group. The OAD group demonstrated marked changes in the direction of elbow motion in the extension range, and the valgus motion pattern during extension was decreased. CLINICAL RELEVANCE: The results of the current study provide a good starting point for further research into the nature of arthritic progression in the elbow joint and the role of debridement arthroplasty.

3-Dimensional deformity analysis of malunited forearm diaphyseal fractures.

PURPOSE: Several biomechanical studies using cadavers have revealed that axial rotation deformity of the forearm bones reduces forearm motion. However, little information is available on the 3-dimensional deformity patterns, including axial rotation deformity in malunited diaphyseal fractures of the forearm. The complex deformity of both forearm bones is difficult to assess on plain radiographs or cross-sectional images. Therefore, we assessed osseous deformity in malunited diaphyseal fractures of the forearm using 3-dimensioinal analysis. METHODS: We examined 21 patients (16 malunions of both forearm bones and 5 isolated radial malunions). Three-dimensional computer models of bilateral radius and ulna were created from computed tomography data. We evaluated deformity by superimposing the mirror-image bone model of the contralateral normal bone onto a model of the affected bone. RESULTS: In 21 radial malunions, extension (n = 17) and pronation (n = 16) deformities were common. This tendency was seen particularly in proximal malunions. Average extension, valgus, and pronation deformities were 18°, 2°, and 16°, respectively. In 16 ulnar malunions, valgus (n = 15) and pronation (n = 12) deformities were common. Average flexion, valgus, and pronation deformities were 1°, 11°, and 6°, respectively. Extension deformity of the radius and valgus deformity of the ulna were correlated with restriction of forearm motion. CONCLUSIONS: Malunited diaphyseal fractures of both forearm bones showed complex deformities, which suggests that 3-dimensional modeling may be a more effective method than standard computed tomography or radiographs. Pronation deformity of the radius may be caused by the supinator and pronator muscles. In addition, the deformity pattern of both bones may indicate that valgus and internal rotation force in the neutral forearm position is applied to both forearm bones after injury. CLINICAL RELEVANCE: Three-dimensional forearm osteotomy, including rotational realignment, is necessary to obtain anatomical reduction.

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.

In vivo three-dimensional motion analysis of chronic radial head dislocations.

BACKGROUND: Forearm kinematics and interosseous membrane function in chronic radial head dislocations sustained in childhood are unknown. Several procedures have been performed to reduce the radial head on the basis of static preoperative assessment in only one forearm position, but clinical results are not always favorable. QUESTIONS/PURPOSES: We investigated the in vivo three-dimensional (3D) kinematics and length changes of interosseous membrane ligaments during forearm rotation in chronic radial head dislocations using 3D CT registration techniques. METHODS: We examined 10 patients with chronic radial head dislocations (seven Type 1 and three Type 4 Monteggia lesions). To quantify kinematics, the axis of rotation (AOR) and radial head motion were investigated using computer bone models constructed from CT data placing the forearm in three positions. We also created six interosseous membrane ligaments and calculated their 3D lengths during forearm rotation. RESULTS: In Type 1 lesions, the AOR was located 2.4 mm from the center of the radial head (COR). The COR translated 2.8 mm sagittally and 3.4 mm coronally. Three interosseous membrane ligaments showed little change in length. In Type 4 lesions, the AOR was located 6.2 mm from the COR. The COR translated 10.2 mm sagittally and 4.7 mm coronally. No ligament showed an isometric pattern. CONCLUSIONS: In Type 1 lesions, the radial head showed relatively stable motion in the dislocated position and the isometricity of the interosseous membrane remained, which supports the concept of ulnar osteotomy. Conversely, the radial head was unstable and the normal interosseous membrane ligament tautness pattern was disrupted in Type 4 lesions. LEVEL OF EVIDENCE: Level IV, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

Open reduction and 3-dimensional ulnar osteotomy for chronic radial head dislocation using a computer-generated template: case report.

We report a case of a radial head dislocation that was successfully treated 8 years after the initial injury, by open reduction of the radial head and 3-dimensional ulnar osteotomy, using a computer-generated template based on preoperative 3-dimensional computer simulation.

Corticoplasty for improved appearance of hands with Ollier disease.

PURPOSE: Only a few treatment options are available for Ollier disease, especially for improving appearance. The purpose of this study was to evaluate the efficacy of partial resection of the cortical bone with curettage of the tumor (corticoplasty) for treating hand deformity in Ollier disease. METHODS: Five hands (3 patients, 30 metacarpals and phalanges) were examined. Windows of thin cortical bone were elevated, the tumors were excised, and the cortex was trimmed and replaced to enhance the appearance. Artificial bone substitute was used as the graft material for 17 lesions to fill the vacant medullary cavity. The other 13 bones had corticoplasty without grafting. Reduction of bone diameter on radiographs and patient satisfaction were rated after an average of 24 months. RESULTS: On average, bony union was achieved 9 weeks after surgery (range, 4-12) in all cases. Morphologic changes on radiographs were rated as excellent or good. Complications and tumor recurrence were not observed, and the range of finger motion and grip strength did not decrease. The level of satisfaction with the outcome was very satisfied for 4 hands and satisfied for the remaining hand. CONCLUSIONS: Corticoplasty for Ollier disease resulted in cosmetic improvement without functional deterioration.

Corrective osteotomy and ligament repair for longstanding radial collateral ligament tear of the proximal interphalangeal joint: case series.

PURPOSE: To evaluate the clinical outcomes of corrective osteotomy and ligament repair for longstanding radial collateral ligament tears of the proximal interphalangeal (PIP) joint. METHODS: We retrospectively evaluated 4 patients with 5 longstanding tears in the radial collateral ligaments of the PIP joints. The average age at the time of surgery was 51 years (range, 40-62 y). The average time from the initial injury to surgery was 31 years (range, 22-40 y). Plain radiographs revealed an ulnar slope at the PIP joint surface with degenerative changes in all fingers. We corrected the slope using a closing wedge osteotomy of the neck of the proximal phalanx secured with a headless screw. We then repaired the radial collateral ligament by overlapping the elongated ligament. Range of motion exercises were started 2 weeks after surgery. To evaluate the results, we compared preoperative and postoperative range of motion, ulnar deviation, instability, pain, and level of satisfaction. Average follow-up was 27 months (range, 18-48 mo). RESULTS: All osteotomies had united at an average of 3 months. We observed no major changes in range of motion, but flexion contracture gradually appeared in 1 high-demand patient. The average preoperative angle of ulnar deviation was 36° and was corrected to a postoperative angle of 2°. The average angle of lateral instability improved after surgery from 22° to 1°. Finger pain disappeared or decreased in 3 low-demand patients but persisted in 1 high-demand patient. Two low-demand patients were very satisfied and 1 low-demand patient was satisfied; however, 1 high-demand patient was dissatisfied with the results of surgery. CONCLUSIONS: Corrective osteotomy and ligament repair can result in a straight and stable joint with a good range of motion in low-demand patients. This method could be a treatment option for carefully selected patients.

In vivo and 3-dimensional functional anatomy of the anterior bundle of the medial collateral ligament of the elbow.

BACKGROUND: Although the anterior bundle of the medial collateral ligament (AMCL) is a critical stabilizer of the elbow joint, little information exists on in vivo and 3-dimensional functional anatomy of the AMCL. The purposes of this study were to investigate in vivo changes in the length of the AMCL during elbow flexion and to clarify the 3-dimensional functional anatomy of the AMCL. METHODS: We created 3-dimensional models of the AMCL and bones from computed tomography data of 4 healthy elbows in 5 different elbow positions. The AMCL was subdivided into 9 ligaments. We calculated changes in lengths of ligaments during flexion and related ligament origins to the axis of rotation of the elbow joint. RESULTS: There were 4 uniquely configured isometric ligaments, where their origins aligned broadly along the course of the axis of rotation in the coronal plane. The medially originating ligaments inserted on the posterior portion of the tubercle of the coronoid process, whereas the laterally originating ligaments inserted on its anterior portion. There were 5 non-isometric ligaments, 3 of which had origins proximal to the axis and became taut only in extension and the other 2 having origins distal to the axis and becoming taut only in flexion. CONCLUSIONS: Isometric ligaments within the AMCL do not originate from a narrow area; rather, they originate from a broader area that extends more medially in the coronal plane than previously thought, which explains how the AMCL reconciles isometricity and robustness. The proximal and distal ligaments act as checkreins that work only at the limits of elbow motion.

Three-dimensional analysis of acute plastic bowing deformity of ulna in radial head dislocation or radial shaft fracture using a computerized simulation system.

BACKGROUND: Little 3-dimensional biomechanical investigation of plastic bowing deformity of the ulna has been reported, and the purpose of this study was to conduct such an investigation to elucidate mechanisms of injury and appropriate treatments. METHODS: Ten cases of traumatic plastic deformity of the ulna in pediatric patients, 4 with chronic radial head dislocations (Monteggia equivalent) and 6 with malunited radial shaft fractures, were analyzed for rotational deformities in the axial plane and bending deformities in the sagittal and coronal planes in Euler angle space by use of a 3-dimensional computerized simulation system with a markerless registration technique. RESULTS: Deformed ulnae with radial head dislocations had 18.7° ± 17.4° of external rotation in the axial plane and 10.4° ± 7.0° of extension in the sagittal plane whereas those with malunited radial shaft fractures had 12.5° ± 12.7° of internal rotation and 6.3° ± 5.6° of flexion displacement compared with mirror images of the opposite ulnae. Absolute values of rotational deformities in both groups were larger than those of sagittal and coronal bending deformities. DISCUSSION: Most major traumatic plastic bowing deformities of the ulna involved rotation rather than bending. External rotational stress on the ulna is suspected to cause radial head dislocation, and internal rotational stress results in radial shaft fracture during falls onto outstretched arms. Therefore the correction of rotational deformities of the ulna should be considered in the treatment of chronic radial head dislocations and malunited radial shaft fractures.

Distal radius osteotomy with volar locking plates based on computer simulation.

BACKGROUND: Corrective osteotomy using dorsal plates and structural bone graft usually has been used for treating symptomatic distal radius malunions. However, the procedure is technically demanding and requires an extensive dorsal approach. Residual deformity is a relatively frequent complication of this technique. QUESTIONS/PURPOSES: We evaluated the clinical applicability of a three-dimensional osteotomy using computer-aided design and manufacturing techniques with volar locking plates for distal radius malunions. PATIENTS AND METHODS: Ten patients with metaphyseal radius malunions were treated. Corrective osteotomy was simulated with the help of three-dimensional bone surface models created using CT data. We simulated the most appropriate screw holes in the deformed radius using computer-aided design data of a locking plate. During surgery, using a custom-made surgical template, we predrilled the screw holes as simulated. After osteotomy, plate fixation using predrilled screw holes enabled automatic reduction of the distal radial fragment. Autogenous iliac cancellous bone was grafted after plate fixation. RESULTS: The median volar tilt, radial inclination, and ulnar variance improved from -20°, 13°, and 6 mm, respectively, before surgery to 12°, 24°, and 1 mm, respectively, after surgery. The median wrist flexion improved from 33° before surgery to 60° after surgery. The median wrist extension was 70° before surgery and 65° after surgery. All patients experienced wrist pain before surgery, which disappeared or decreased after surgery. CONCLUSIONS: Surgeons can operate precisely and easily using this advanced technique. It is a new treatment option for malunion of distal radius fractures.

Arthroscopic debridement of the humeral capitellum for osteochondritis dissecans: radiographic and clinical outcomes.

PURPOSE: Although arthroscopic debridement of the humeral capitellum is an accepted procedure for osteochondritis dissecans, some patients develop radial head enlargement or osteoarthritic lesions after the procedure. The aim of this study was to investigate the radiographic and clinical outcomes of arthroscopic debridement and consider its indications. METHODS: We retrospectively evaluated 106 patients who had arthroscopic debridement between 1997 and 2007. Surgery was performed after closure of the capitellar physis. We categorized the patients into 4 groups by lesion size and by whether the proximal radial physis was open or closed. The average patient age at surgery was 15 years (range, 12-18 y), and the average follow-up period was 13 months (range, 8-46 mo). RESULTS: In patients with large lesions and open proximal radial physes, radiographic and clinical outcomes were poor. Three of 4 patients developed early osteoarthritic lesions of the radiohumeral joint, secondary to radial head enlargement. Radial head resection was required in 2 of 3 patients. Conversely, osteoarthritic lesions did not occur, and we observed noteworthy improvement in elbow pain routinely after the procedure in the other 3 groups. For range of motion, clinically important changes were not observed. Overall, postoperative elbow pain was absent in 89 patients. Mild pain was present in 15 patients and moderate or severe pain in 2 patients. A total of 90 patients returned to sports at pre-injury levels. Time of return to sports varied from 1 month to 5 months (mean, 2.4 mo). CONCLUSIONS: Arthroscopic debridement of the capitellum can provide excellent short-term results for the treatment of osteochondritis dissecans. However, it is contraindicated in cases with large lesions when the proximal radial physis remains open.

Three-dimensional analysis of cubitus varus deformity after supracondylar fractures of the humerus.

BACKGROUND: What is thought of as a classic "cubitus varus" deformity usually consists of varus, extension, and internal rotation. However, its 3-dimensional (3D) pattern with 3D imaging has not been reported. This study aimed to obtain such 3D patterns using 3D bone models created from computed tomography data and evaluate the accuracy of conventional radiographic and clinical methods of assessing the deformity. METHODS: Imaging of 25 humeri of 25 patients with cubitus varus deformity caused by previous humeral supracondylar fractures was performed. The deformity was assessed by superimposing the 3D bone model onto a mirror-image model of the contralateral normal humerus. The 3D deformity pattern of cubitus varus was evaluated based on the 3 deformity components. Values obtained from conventional radiographic and physical measurements--that is, humerus-elbow-wrist angle (HEW-A), tilting angle (TA), maximal elbow flexion angle (MEF), and internal rotation angle (IRA)--were compared with those from the 3D technique. RESULTS: Of the patients, 44% had varus, extension, and rotation deformities of 10° or greater; 20% had varus and extension deformities of 10° or greater; 16% had varus and internal rotation deformities of 10° or greater; and 20% had varus deformity only. When the 3D measurements were considered accurate, an error of 10° or greater was found in 8%, 24%, 8%, and 44% of cases in terms of HEW-A, TA, MEF, and IRA values, respectively. CONCLUSION: Of the humeri, 80% had other bony deformities in addition to varus and 20% had isolated varus deformities. HEW-A and MEF showed reasonable accuracy as measures for the degree of deformity, whereas TA and IRA were found to be relatively inaccurate.

Open repair of foveal avulsion of the triangular fibrocartilage complex and comparison by types of injury mechanism.

PURPOSE: Little attention has been paid to injury mechanisms of foveal avulsion of the triangular fibrocartilage complex (TFCC). The purpose of this study was to determine whether the mechanism of injury is associated with different anatomic disruptions as well as different preoperative clinical symptoms. We also evaluated the clinical results of an open repair method for foveal avulsion according to the mechanism of injury. METHODS: Fifteen patients with a traumatic foveal TFCC avulsion were treated with an open repair technique. The injury mechanism was forced wrist extension in 10 patients (group E) and forced forearm rotation in 5 patients (group R). All patients in group E and 3 in group R showed positive fovea signs. Surgical and clinical findings were compared according to the 2 types of injury mechanism. RESULTS: Foveal insertions of TFCC were found in surgery to be disrupted in all 15 patients. In addition, disruption of the dorsal styloid insertions of the radioulnar ligament showed a significantly greater association with group R than with group E. Clinical results showed significant postoperative improvement but were marginally different between the 2 groups. CONCLUSIONS: The most common mechanism of foveal TFCC avulsions is forced wrist extension, an injury that commonly shows positive fovea signs and leaves the dorsal styloid insertion of the radioulnar ligament intact. Forced forearm rotation is the second most common injury mechanism that is more frequently associated with disruption of the dorsal styloid insertion. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.

Osteosynthesis for longstanding nonunion of the lateral humeral condyle in adults.

HYPOTHESIS: Osteosynthesis for longstanding nonunion of the lateral humeral condyle in adults has a high rate of complications, including failure of bony union and restriction of elbow motion. We hypothesized that rigid fixation may contribute to higher union rate and the placement of the condyle fragment with proper tilting may minimize the reduction of elbow motion. MATERIALS AND METHODS: Ten patients were treated with osteosynthesis. Average age at operation was 38.6 years. Three patients had dysfunction of the ulnar nerve, 2 experienced pain, and 5 had both presentations. According to Toh et al's radiographic criteria, nonunion was categorized as Group 1 in 2 patients and Group 2 in 8 (J Bone Joint Surg Am 2002;84:593-598). We performed osteosynthesis with iliac bone graft and ulnar nerve anterior transposition, with efforts to fix the fragment rigidly and to manage the fragment position properly. RESULTS: Osseous union was achieved in all 8 Group 2 patients, while 1 Group 1 case showed delayed union and the other did not achieve union. Pain resolved and ulnar nerve symptoms improved in all cases. In 9 patients with union, total arc of motion was reduced by an average of 20°. The preoperative mobility of the condyle fragment determined by maximum flexion and extension lateral radiographs had a correlation to the postoperative loss of motion (P = .047); however, loss of motion was less than that expected by radiographs. CONCLUSION: Osteosynthesis appears to be indicated for Group 2 nonunion with pain. Rigid fixation with care of the position of the fragment is important for the good outcomes.